commit 01 amnmm swot of itpforo unrvntifg

MIOCENE STRATIGRAPHY AND PALSEONTOLOGY
OF SOUTHWESTERN ECUADOR
mßMtTfm to
a mommoTim
mm school of iqpmtt satwms om
$m
commit 01 amnmm swot of itpforo unrvntifg
II ffclffXAL FOLFXLWIf OF fit RSqattSIQEKTS FOR TBS PMREI Of
BOCTOI Of faiiOSOHiT
ill)i 11(11iiiinHHlii,!■ i,l*,,««■ PIMM
By
Jay Olenn larks
June, 1961
X certify that Ihave read tbie thesis and that In my
opinion it Is fully adequate, in scope and quality, as
a dissertation for the degree of Doctor of Philosophy.
Icertify that Ihave read this thesis and that in my
©pinion
it is fully adequate, In scope and quality, a
dissertation for the degree of Doctor of Philosophy.
E^~EEJy
J(^jlw\m\n7lsnmWMimi \mmmmimmttmm»imm*mm*mmmmmmmmmnHmwm\iiMt-*mm
Approved for the Committee on Oraduste Study.
mmmm* *mmmn.nn
iii
TABLE OF CONTENTS
List of illuatratlons." ".""*""""»*»*«*"»**»*«".***
*##*«♥♥.#*■#.***###**♥#*»*♥**"»'#**##**»»»*'♥
11i
>.€*
i
wiott*"**#■**■#********"****»"#**»"«#*»***■»*""
;,LGOWio«|pllotitlt*
*#♥***«**"****-"**«*»*«»*"*»»»"*"♥
if
*
a
**
stataiaant of t m v ©aia* .*.**»"***"*"»♥*****♥**.#.»
Gao 1 1a ";-.:;" in and geologic setting,"
■ I% t t . -".Fapiiy » « * «*****,-«*».#«*"****"»*"*****>".>#*.#*.*
Oasaral atata&ent*
13
14
1 lacuna formationa of the Jrrogreao Basis,**..
Sublba ja foraation. ""*»#*»*#**"*"******
Jr^r© ijpr aso * onus,ii^s* *«####******##«##*#♥
,♥
Tha Daule formation of tbc aula aaliu
ago
.«.»«""""",,"*.,>".""""«""»"«*«
C o rrsla tloi. and
Geologla Jii,stoi*3F«> «*#».#*"*«»#♥>**»»»*■##*«*»*♥«"****
ona» »*****#«*»*»**#*«-"»»**"«*»■"""»"""**""
itaiaati© description of speclea*
iPa lacyj&oaa*"««***** " * + "»»*>*»***# #*»""****#**
iSoap&opoda *"#*«.** " ** + **""""**"*"**"*-»"**
BQ
.*.***♥»»....,.#.
****«,„*.##»****.*.♥...*.»
..*
..*",*"*"*"«"*«
««".
\j»as wyoj^oos»#«*#.♥#***#-"""#*»*«♥*"»*«»*»*#""#*
Caj3«a Jtopooia .**#*«#«.*♥#*»*'*"»#■**»***#*«*»■*"«#
C3TU& w&Gd €-* .*#*♥#*
#»*»»#*
#-»»#*"#. **♥#*#«*"»♥«»»
ixplaßatioas of plates
..^ikafia* iod of jpjtfiiiii J» #♥** " *»#»»#♥# # « # "#■*■» * #
jlai&atfi'j.ofiL of pistil «&***♥"##♥##*"»♥#»
«#»*♥*
Mplaitatiam of plate 3* *»".««..«.". .«*"»."« *
Sxpla&atiom of plate 4.""***""
lasation of plate 8* *«"*"" «****"-***«'*«"*«
1 ©i J)Jillt# a*#«*##*»*. #*#"*#**"*#**
a of plat© 7# "»"**■*♥*»""""»**"**»*
gsplafrntioA of plate 8* *«"««"""*»*«"»**.«-*«
*«
planAt lon of plate 9*»«*«**.**. *"""»"**.»«
!i
iX loipr&pijy **##*###**#*#**#*****"*"*«**"#"#»*»**
i»v
19
20
*3«l
40
51
*^4;
©0
ou
154
*wv
&<fei#
&5u
sojs
&w«#
234
*»♥***«**,,.»»
23§
<A*> i
238
83t
240
&%*.
IV
LIST OF ILLUSTRATIONS
OFSOUTHWESTERE
N
CUADOR
MIOCENE STRATIGRAPHYand
PALEONTOLOGY
14
£
vie« eastwara to the town of
3
fewn of Pedro r&fele Gomez
4
Correlation of southwestern fcuadorena
. iocene formations
8
Cheek*llst of subibaja formation Mol-
6
ffuftaers ana percentages of species in
j£cuadoresxi and Peruvian formations
Sd
t
stratlgrapbio setueaee of £regreso Basin
..ollusca
24
8
Occurrences of species common to Progress
and Daulc- aalns
34
9
sfratigreptilc sequence of Baule
Molluscs
frograso
..
-*
luscs
IM
17
&0
ijaaia
88
10
Occurrences of southwestern Seuaaeream
Molluscs in ether regions
4?
11
Qtnerallssed correlation chart of iHocaaa
formations of northwestern South
America ana Panama
Si
IS ialeogeographic map of southwestern
Ecuador at beginning of Middle
time
Plates 1-9
S3
ABSTRACT
This study of the environmental and chronologic
relationships of two sedimentary basins is based
analyses of the mollusean fossils*
on
The Progreso and
Daule Basins of southwestern Ecuador are physiographic
depressions, and in Miocene time they were submerged.
The Miocene sediments in the basins are thousands of
feet thick. The exploration of these sediments by the
International Ecuadorean Petroleum Company provided the
material for this study.
The Miocene strata of the Frogreso Basin are
divided into the SuMbaja formation (Lower Miocene) and
the Progrea© formation (Middle Miocene ]"
The Subibaja
formation ia mainly slltstone, contains 60 species of
Mollusc*, and was deposited in progressively shallower
water of over GO to about 3 fathoms.
It correlates with
the Lower Zorritos formation of ?»t\i and, approximately,
with the Burdlgalian Stage of Europe,
The Progres©
for-
mation is mainly sandstone and sllty clay, has yielded
41 species of Molluscs, and was deposited in shallow
marine and brackish water.
It correlates with the Varie-
gated beds, Upper Zorritos, and Cardalitos formations of
northwestern Peru, with the Baule formation, and approximately with the Vindobonian Stage of Europe.
2
The marine strata of the Daule Basin belong to
the Daule formation (here named), which contains 44
species of Molluscs and was deposited in a shallow sea.
The Daule formation correlates with the Progreso formation, the Cucurrupl and lower Tuber* beds of Colombia,
and the Oattin formation of Panama.
Correlation with the European Stages (Burdlgallan
and Vindobonlanj is made through reference to published
studies on the Caribbean Miocene formations*
One
California formation, the Bound Mountain silt, appears
to be equivalent to the upper Subibaja and lower Progreso
formations.
Thus, the Subibaja formation is about equal
to the Reliaian Stage of California*
The Progreso Basin was a submerged Oligocene
graben that survived until Late Miocene time. It was a
shallow embayment of the Pacific Ocean, open to the
south, subsiding rapidly until the end of Middle Miocene
time.
The Daule basin was a shallow, submerged geo-
syncllne during Middle Miocene time.
It also was an em-
bayment of the Pacific, open to the north, subsiding
relatively slowly until the end of Middle Miocene time.
The Daule and Progreso marine embayments were separated
by the former Colonche Peninsula during th®
Miocene epoch.
Both basis hsve been tilted and locally faulted since the
Middle Miocene, but have not sunk below sea level.
3
One hundred and twenty-one saollusesn species are
discussed systematically, and 52 are described as new.
The report is illustrated by two maps, two photographs,
sight charts and nine plates.
m*
PIG. i. MIOCENE STRATA OF SOUTHWESTERN ECUADOR
4
INTRODUCTION
Purpose of the Report
The purpose of this report is, primarily, to
determine the environmental and chronologic relationships between two basins of Tertiary deposition and,
secondarily, to describe the mollusean fossils en-
countered In the two basins*
lbgat!gn of the Areaf Studied.
The two basins that form the subject of this
report are in southwestern Ecuador.
Ecuador is a South
imerican country approximately 4§o miles in length from
north to south, and 400 miles from east to west.
It Is
divided naturally Into three contrasting, physiographic
provinces: the coastal region paralleling the Paelfis
coast, the Andean Cordillera, and the eastern lowlands,
which are Jcnown as the Orients.
The basins to be dis-
cussed lie in the southern portion of the coastal region,
froa one to three degrees south of the equator, which
passes through the center of tha country,
The locations
are shown on the map, figure 1.
gource of Materials and Information
The fossil specimens and data used in this report
were derived from the geological explorations for oil of
the International leusdorean Petroleum Company, Ltd. This
company was formed in 1944 by a union of interests of the
International Petroleum Company, Ltd, of Toronto, Canada
5
and the Standard Oil Company (lew Jersey)*
Exploration
had begun In 1938 uno*er the International Petroleum Com-
pany, Ltd., and was most fully developed In the years
1940-1947.
During these years, topographic, gravimetric,
seismic, core-drill, and deep drilling surveys were conducted, with two or more geological mapping parties in
the field most of the time.
The paleontologies! staff,
which usually consisted of three micropaleontologists and
one ffiegspaleontologlst (the writer), examined field and
subsurface samples in the laboratory located
In Guayaquil.
411 these means of exploration contributed to the information on which this report is based; but the fossil material
and most of the stratigraphic information used for the report
came only from geological field parties and core-drill
samples.
Tha author, in addition to doing paleontology in
the laboratory, conducted a geological survey m$ supervised a core-drilling program In the Progreso Basin.
History of Geological Exploration
The earliest geological studies of importance in
Ecuador were made by Teodoro
iolf,
a European
, who
was
the state geologist during the latter part of the nineteenth century.
The results of wolf's studies are con-
tained in his volume,
Qeogrsffa £
del Ecuador,
Leipzig, 1892, which is still the finest reference avail-
able on the geography, culture, earthquakes, and general
6
geology of Ecuador.
The geology of the entire country is
outlined with remarkable correctness, considering that
wolf's was the first attempt at such a project; however,
he sad©
no detailed studies of the Progreso or Baule
Basins, and his geologic map shows most of southwestern
Ecuador as covered by Quaternary rocks.
Oil in tha form of seeps and tar pits has been
exploited on the Santa Elena Peninsula, west of the Pro-
greso Basin, at least since the days of the early Spanish
explorers.
Drilling operations by
an English company led
to the discovery of producible oil la 1914, and in succeeding years a large number of papers on the pussxllng
geological features of the Santa Siena 2mlnmla were
published,
These papers dealt principally with the Eo-
cene 011-hsarlng rocks of the region and, to a. lesser extent, with the Cretaceous, Oligocene, and quaternary strata.
Ho deposits of Miocene age were recognised on the Santa
Siena Peninsula.
Approximately W papers, b®s&&
on
studies by the peninsular geologists, appeared In the
years 19E3-1938, Of these papers, 16 were by George
Bhepp&t&*
Hone of thaa describes in detail the geologic
features of the Progreso or Daule Basins.
In 10E3 the Standard Oil Company of California
drilled an unsuccessful new field wildcat, Qjuljano-l,
In the center of the Progreso Basin, near Baj&da.
7
Miocene sediments wore enooun tared throughout most of
the section drilled. Late in the same decade
, the
Inter-
national Petroleum Company, ltd. also drilled two unsuccessful wildcats In the Progreso Basin,
in 1931 and 1932, A. A. Olsson, in his publications on the geology of northwestern Peru, briefly re-
ferred to the Oligocene and Miocene rocks of the
Progreso
Basin, and described Ecuadorans molluscan fossils.
George Sheppard published The geology of south-
western Sousdor (London, Thomas Murby & Co.) in 1937.
Most of tha £61 pages constituting the text of this vol-
ume refer to geological and other features of the Santa
Siena Peninsula.
Only two pages
are devoted to Miocene
rocks, which are mentioned in very generalised terms.
The following sentences contain the gist of $happsrd f e
Statements concerning the Progreso and Daule Basins*
"Tertiary sediments of Miocene age occur
throughout an extensive region west of
Guayaquil, and may be correlated with the
formations in the vicinity of 2orritos,
in Peru." (p. 133)
"Excellent sections in ths Miocene are
found along the railway cuttings from Ban
Jose" de iaen (now the town of Progreso) to
Playas, and farther west these exposures
occur almost as far as Zapotal." (p. 134)
**Xt has been estimated that at least 5000
feet of Miocene deposits are represented
in Ecuador...the Miocene embayment was very
extensive.,.Miocene formations underlie the
greater part of the Gulf of Guayaquil, and
have been recognized along the valley of the
Rio Baule.'* (p. 135)
8
The most recent phase of exploration in coastal
Ecuador began in 1936, when the International Petroleum
Company, ltd. of ftoronto, Canada acquired a large part
of tha coastal region aa an exploratory concession,
In-
tensive geologies!, .geophysical, and drilling programs
were under way by 1940. Operation®
were terminated In
1947, bet only after the drilling of 20 unsuccessful deep
siiaeat tests &n& an expenditure that in Ecuador alone
exceeded 111,0 00,000.
alone seven
In the Progreso
wildcats and numerous core-holes were drilled, over 800
pits ware dug, and detailed gravlmeter, seismograph and
surface geological surveys ware conducted.
In 1944 the
&euadoraea venture was refinanced, and the International
£euadorean i":etroleu» Company was formed sith financial
backing of the Standard Oil Company (Kew Jersey).
main result of this work was a
huge
amount of strati-graph
ical Information about the rrogreeo Basin.
this work forms the basis for the
The
4 portion of
present report.
These same investigations in the coastal region
h&vs given rise to some recent publications.
Bans Thai-
mann has reported on Cretaceous, Paleooene, Eocene, and
Miocene miorofossils (see bibliography).
3tainforth and
Stevenson (1946) have described new foraminifers from the
Tertiary.
Gtainforth has published an excellent report
covering the micro fossil assemblages of Middle Socene to
9
Upper Miocene strata, with deductions
ecology.
as to their paleo-
Stainfortb and (the late) 3. A. Cushman have
In preparation a paper on the Eocene foraminifera of the
coastal region.
Operations in tha Orients were begun by the shell
Company of gouador In 1938, simultaneously sith those of
the International Petroleum Company In the coastal region.
In July, 1948, there appeared an article by H*3* Tschopp,
which combined summaries of the knowledge of both compa*
nles, and which was published In an obscure awlss periodical of
limited circulation.
—
. . . .axe yon Ecuador,
_-....,. ..-,-..■.,.^-.i\-:«j,»
mz^w*m**M*<^.tt>^mm&mmr
The article, Geologisehe
Is the most complete treatment of the
geology of Ecuador since
■*«
Pelf's treatise of IS9B. Tim
Progreso Basin Is mentioned, the subibaja and Progreso
formations briefly described., and the basin*s tectonics
suggested.
The Subibaja formation is ascribed to the
Aqultanien State, and the Progreso formation to "Burdlga-
llan and
younger. H
The geologic map of South America, 1950, published
by tha Geological, society of America, shots the general
geological features of Ecuador.
The accompanying text on
the coaatal region, which has not yet appeared, will Include a discussion of the llthology, paleontology, and
palcogeography of the Miocene strata.
10
The present dissertation was prepared mostly during
194? and 1948.
It is a detailed study m\m compared with
the existing literature concerned with
jgeuadorean
geology.
It will be the first published report to deal exclusively
and comprehensively with the Miocene molluscan fossils of
southwestern Scuador,
11
ACKNOWLEDMENT
Stanford University and the International Petroleum
Company, ltd., of Toronto, Canada generously cooperated
with th© author in furthering the writing of this disser-
tation. Peniiaslon to publish was
granted by the direc-
torate of the company; and Mr. 0. C. fheeler, formerly
chief geologist and now a director, gave both encouragement and criticism. Research was done in the school of
Mineral
jsslenoes of
aided in th©
Stanford University, Br. 4, U* lean
systematic studies, which constitute the
principal contribution of this report, and is gratefully
acknowledged as an inspiring instructor in the more complex ramifications of taxonomie procedure.
Composition
of the report was supervised by Professor S, §« Huller.
The writer had previously received most of his training
In the principles of bio stratigraphy at Stanford University from Professor Muller and Dr. Hubert G. Sehenofc.
The collections of fossil material and strati-
graphic information were accumulated by the field geologists of the International Ecuador ©an Petroleum Company,
a subsidiary of the International Petroleum Company, Ltd.
and the Standard Oil Company (Hew Jersey)
.
The geology
of the Progreso Basin was made known mainly by Ft. I.
Lsndes, and the geology of the Daule Basin by o*L. Haught.
Others who aided materially in the field
vara
C* A, Roig,
12
William Beuck, John Browning, and D. H. Elliott.
Micro-
paleontology played a large part In defining the strati
graphic units of southwestern Ecuador.
-
The competent
and copious work of F. V. Stevenson, F. H. Pulitz, D. L.
Frlzzell, Benton Stone, and R. M. Stainforth, much of It
under the able direction of H,
E,
Thalmann, is of Inesti
mable value to the present report, and to the general
knowledge of the paleontology of Ecuador. The geological
exploration of coastal Ecuador from 1941 to 1946 was
directed at various times by W. W. Waring, G. A. Durham
(chief geologists), R. W. Pike (assistant manager], and
W. E. Wallis (manager).
The illustrations of fossils are In part drawings
by Mary Barna3 made In Guayaquil, Ecuador, and in part
photographs by Alexander Tihonravov, made at Stanford
University. The fossil material was prepared for examina-
tion, transportation, re -examination by Ruperto Laniz of
Stanford University. Most of the specimens and Illustrations used for this report have been deposited in the
Faleontological Research Institution, Ithaca, New York,
through the kindness of Dr. Gilbert D. Harris.
The re-
mainder of the material, consisting mainly of paratype
specimens, is deposited in the Stanford University type
collection.
The Creole Petroleum Corporation of Venezuela
aided in the reproduction of graphic material and the
typing of the manuscript.
13
STATEMENT OF THE THESIS
Two basins of tertiary deposition contain strata
of Miocene age, and are sow separated only by a narrow
range of hills. During Miccene time tha two basins wore
embeysents of the Pacific Ocean, separated by the former
Colonche Peninsula.
The irogreso Basin existed as a
rapidly subsiding grabea during larly and Middle Miocene
time, while the ©aula Basin was a slowly subsiding, shalIXUIHisL illy IXUv VV V^JtVAVk? |J-IJ9I, 3v<llllilll2i fJI Uvv
low geosync line.
M
These postulatlone are based on studies of the mollusoan fossils and stratigrap&le information from the two
basins.
14
GEOGRAPHIC AND GEOLOGIC SETTING
The portion of southwestern Ecuador discussed In
this paper lies in the coastal region between one and
three degrees south latitude and
longitude.
79* SO* and 81® west
Within these limits exist six geographic
sub -provinces ; the Santa Elena Peninsula, the Estancla
and Azdcar
Hills, the Progreso Basin, the Colonche Range,
the Daule Basin, mnd the western slope of the great Andean
Cordillera.
Only three of the six geographic units are
extensively treated in this pepert
the Progreso and Daule
Basins, and the unit whien separates them, the Colonche
Range.
The .Progreso and Daule Basins are basins in both
the geographic and geologic senses.
The Progreso Basin
is bounded on the southwest by the Estancla and Azdcar
Hills, on the northwest by the Sayd Hills, and on the
northeast by the Colonche Range.
The basin drains through
a gap between the Azdcar and Estancla Hills on the west,
and southeasterly to estuaries of the Gulf of Guayaquil.
The Daule Basin is bounded on the southwest by the
Colonche Range, on the northwest by the Balzar Range, on
the north by moderately high mountains at the latitude of
Quito, a fourth of a degree south of the equator, and on
the east by the piedmont area of the Andes Mountains.
9
1
q ea
r-!
0..
c0
*H
o
Mi
♥H
WLj*
w
13
O*H **
*
b
Ov
{.!".
7
'"M O ,-:'.'"
o/ a
g I*
'
'-..
.
.-■
'
i
i
O 8
.
:
'
ad
'
a?
>
'■
*'V
■
5
I
4* & H
.
■.
«
■..-'■
fa m is
■h ccS j3
!> PQ c 9
i
p*
Ml
*
H
ts©a
15
Runoff from the Daule Basin flows into the Daule River
system, which drains southward into the Gulf of Guayaquil.
The Progreso Basin is 65 kilometers long and 37
kilometers wide on th©
average, thus having an area of
approximately 2400 square kilometers.
It Is a semi -arid
region consisting of low, rugged hills and some plains,
in broad aspect rising from mongrove swamps adjacent to
estuaries of the
oulf of Guayaquil northward to the Sayd
Hills. The Mils are covered by brush and forest,
whereas
*
tn c
a© v
the plains, underlain by shale, support grass in winter,
"
but are bare by late summer. Small communities and towns
are widely spaced throughout the region. The largest of
oresti
these is the town of Progreso (formerly known as Amen, and
also called Juan Gomez Renddnj, which has a popxilation of
1
4,300 persons. It is located on the only all-weather road
m**mmm*m*mm.m.m.**m.m.m.**m.***.m.****-m****m*»m.-mm,m
1
r mmmm*»mmm.m*mmm**mm***.mmmmmm*.**mm
Population figures for 1946 through courtesy of jDuls
Plaza 1., Guayaquil*
and the only railroad servicing this region.
A view of the
country just west of Progreso is shown in figure 2.
The
agricultural products of the sparsely populated region are
provided mainly by small hillside farms, banans planta-
tions in some of the valleys, and grazing land of poor
quality.
The chief ways of communication are burro trails,
a few dry-season roads, and the narrow-gauge railroad and
the all-weather highway which connect Guayaquil with the
16
Pacific coast.
Guayaquil,
eagt
of the Progreso Basin,
is the largest city in Ecuador (population -between 240,000
11
and ,250,000 persons i, and Is the country's only major
1 Population
figures for 1946 through courtesy of Luis
Plag| li, Guayaqui1,
port.
It is the principal outlet for the agricultural
products of both the Progreso and Daule Basins*
The Colonche
Range (Cerros de Colonche] is
heavily forested mountain chain that extends northwest
from sea -level at Guayaquil to the sea-coast between
Punta Illote and the San Lorenzo Peninsula.
elevation is between 600 and 600 meters.
Its average
The rain-forests
on its slopes contrast sharply with the sparse vegetation
of the basins on either side.
The range Is drained by
streams that flow either westward to the Pacific Ocean or
eastward to th®
Daule River.
The
entire chain Is 150 kilo-
meters long and has an average width of about 16 kilometers.
It is the physiographic feature which separates the .Progreso Basin, both geographically and geologically, from
the Daule Basin.
The Daule Basin Is 225 kilometers long and nearly
96 kilometers wide, thus having an area of approximately
21,500 square kilometers. It includes a large, semi -arid
tract In the south, a tropical forest in the north, and
heavily wooded slopes on the west.
Its eastern limits
consist of lands that rise toward th©
steep
western face
-
9-
CD
,
-O
r» O
o
I
p.. <i<
J
;
,
-
'
.
.
'3
k o
o
£l
jq
-p
o
1
.'
I
©
(Q
-C
"
O
rH
jjg
_n
>
.
0 3
.*
H
3
O © o\
r
j
I
t*i
«
&0
PR
17
They support tropical vegetation that
of the Andes.
merges with the rain-forest of the Andean front.
The
lower reaches of the Daule River are level, grassy
plains close
to sea -level, but the tributaries drain
rugged, hilly country.
This basin also is sparsely
settled. Communities exist as centers for small hillfarms ©long
ranges,
the east flank of the Colonche and Balxar
Pedro Pablo Gomez, a town typical of the hill
country, is shown In figure 3.
Several towns border the
Daule River, which provides them with a year-around
waterway.
The eastern limits of the basin include part
of the well-watered Andean piedmont area. Here the farms
are large, producing cacao, coffee, bananas, and some
cattle. The town of Babahoyo, with 16,000 to 18,000 In-
habitants,
is the center of the eastern Daule region.
1
Population figures for 1946 through courtesy of Luis
Plaza M, Guayaquil.
,
***.m.mi*.mi*mmim*m.m.**m* m*mm.**'mm.mm.**m.*.mm*.m.***mm.********m.*.**
m**»*.*.<m*****»mi******immnm*.m
The country along the lower portions of the river, about
60 kilometers north and east of Guayaquil, Is partly
Inundated during the rainy season from January to May.
The geology of the three regions Is rather complex.
The Progreso Basin is bounded by normal faults.
It is filled with Tertiary sediments some tens of thousands of feet thick, which rest on basement rock that is
presumably Cretaceous In age.
The Colonche Range is
formed mainly of tilted sedimentary and volcanic rocks
*
CORRELATION OF SOUTHWESTBR
AGE
BCUADORjiAK
MIOCENE FORMATIONS
DAULE
PROGRESO
BASIH
FORMATIONS
BASIH
FORMATIONS
n
». mmm* I■I I| im mm111
1.1 ii.nir.nm
m
Lower Miocene
*j\*mmf.
tti*\f\*^sf*,*r
memmmmmmmmmmmmmmw*
m\m\mmmmmmmmmmmmmmm
01!gocene
Fig. 4.
mmi
mimm
mmmmmmmm <** impilyn-i.nmi j»
.pip
Subibaja
-,
im.
mn ■-..hh—ip. ■»■■l»
I
mim.
mil
Lower
11
calcareous
■■
»!ini>«ii»iiPinnii»r,iiMiinpii-iiiipii,
ni.TipPiPiniliiinliiriiiii.il
in ill.ii ill
in
Zacacbdn
member
i Salba
member
"—"
mmmmjimmimmmiimwmmmmmmmmm.muiww
*W***-****m**l*eWew*mWmmm^^
Bos Bocas shale
Chart showing the correlation of southwestern
Ecuadorean Miocene formations based on mollusesn
fossils. The uppermost strata of the Progreso formation
are fosslliferous, whereas unfossiliferous sediments lie
above the fosslliferous beds of the Daule formation In
th© ©astern part of the Daule Basin.
18
of Cretaceous age,
Th© Daule Basin is relatively shal-
low", and is composed of Tertiary and quaternary Strata
of sedimentary and volcanic origin,
Th©
Tertiary strata
rest on a basement of igneous and metamorphio rocks attributed to the Cretaceous epoch.
19
STRATIGBiPHT
General statement
The Miocene strata of the Progreso Basin are shallow
water marine and brackish- water sediments at least 10,67b
feet thick. They lie conformably on marine shales of
Oligocene age, and their uppermost layers are exposed to
erosion.
Th© oldest Miocene strata were deposited in
waters of the greatest 4epth, and the younger strata were
deposited in progressively shallower depths of water. The
marine, older strata constitute the Subibaja formation,
which is divided Into the
and Zacachun members.
The
younger strata constitute the Progreso formation, which
lies at the surface of a large part of th©
.Progreso Basin,
lbs geographic and stratigraphic relationships are shown
on the map, figure 1, and tha correlation chart, figure 4.
The Miocene strata of the western portion of the
Daule Basin are sediments of shallow-water marine origin,
&M they compose the Daule formation.
These Miocene beds
lap over -the upturned edges of Oretaeeous rocks at the
western and southern margins of the
basin. Oligocene and
older Tertiary strata may lie beneath them in the mors
central portions of the basin,
stratified non-marine de-
posits derived from the western slopes of the Andean Cor-
aillera lie on the marine Daule strata in the eastern
portion of the Daule Basin. Since these later deposits
are not fosslliferous, their age cannot be determined
20
exactly, and the possibility exists that some of them
may be conformable with the strata of the Daule forma-
tion.
The Daule formation, which Is approximately 3500
feet thick, includes three members: the "Lower calcare-
ous, * th©
"Blue siltstone,'* and the "Upper calcareous,"
The geographic and atratigrsphic relationships are shown
on the map, figure 1, and the correlation chart, figure 4.
Miocene formations of the Progreso Basin
SUBIBAJA FORMATION
Geologic data.
The Bubibaja formation is named
for the village of Subibaja, which Is 6E.5 kilometers
due west of Guayaquil.
The type locality is ten kilo-
meters south of the village, and extends in a southwesterly direction from a point about 350 meters south-
west of the village of Zacachdn. rho formation is exposed as an elongate band for 14 kilometers to the north
and for 30 kilometers to the south of Subibaja.
The north-
ernmost portion widens, extending nearly 30 kilometers to
the east. Tn© thickness is 1800 feet at the type section,
where the formation is divided into the Saiba and Zacachun members.
Th© lithology of the members is as follows:
saiba member i siltatone-masslve, dark gray,
locally hard with calcareous cement, usually
containing numerous foraminlfers, and /trading
into shaly and sandy phases. Some massive,
friable, fine-grained sanastone near middle
of member. Occasional bands of concretionary
limestone up to on© foot thick in lower onethird, Massive shale, with speckled appearance Cue to foraminlfers, predominant near
21
base. The peleoypod Kuculana sporadically
abundant in upper two-¥Hrls,
Weathered
color reddish-brown, A deeper water facias
is apparent south of the type section, and
her© the slltstone Is highly calcareous and
weathers to a thin-bedded, shalky rock.
Zacachun member t shale, slltstons, and
fine- grained sandstone* Chiefly greenishgray, friable to moderately Indurated siltatone with shaly and sandy phases. Pyrite,
glauconits, mica, and carbonaceous fragments common throughout. Shale gray,
usually barren, la thin beds and lontlcles.
Sandstone fine-grained and friable, usually
containing megafosells. Stratification
irregular, often cross-bedded. Miorofosslls rare in upper portion, more common
toward base. Megafosells locally concentrated throughout, weathered appearance
tan with reddish streaks ana specks of
llmonite stain,
The topography formed over the formation is sub-
dued, wit.fi low ridges, knolls, and gentle swales In the
region near and south of subibaja,
Some higher
hills
(relief estiiaateo to be 200 meters) are present in the
4
structurally
more complex area north of Subibaja, be-
tween Carrlzal and Las Masas.
The beds of the isublbaja formation dip generally
toward the center of the Progreso Basin.
The entire for-
mation was deposited In the upper ncritic zone of a tropical sea; this contention is baaed on the lithology of the
sediments, tha evidence of the Foraminifera,
and the
mmmmmmmmmmmmmm.mmmm.mmmmmmmmmmmmmmmm.mmmmmmmmmmm>m>mmmmmm*mmm.m*m
1 k summary of the mieropsi eontological evidence is contamed in the paper by stainforth, 1948, p. 143.
22
studies of the fossil mollusks as given in ensuing paragraphs.
Paleontology.
The mollusks are the only fossils
of the Subibaja formation which have been studied for
this report, although foraainifers constitute a large
proportion of the organic remains* Sixty-one. sollusean
species are identified, SI of them from ths type section
and 30 more from the Garrizal and las Mesas sectors of
the Progreso basin.
A
check-list of the Subibaja forma-
tion mollusks may he found in figure 5.
Of the il species
are new or
not
ana
subspecies of Molluscs, 41
identifiable fro®
the available literature.
This large proportion of new species apparently reflects
the scarcity of Information available on Lower Miocene
strata of northwestern -South America,
The remaining EO
species have th© following approximate stratigraphic
ranges in other regions:
Kiddle? to Upper Oligocene,
1661s Oligocene to Hecent ,
lower Miocene to Hecent*
Lower Mloeens only,
Lower to Middle Miocene,
Middle Miocene only*
1 species
**
1
1
0
0
5
»«■
n
These species and their occurrences in other regions are
slbown on the chart, figure 10.
Three previously published species provide interesting data
on Lower Miocene paleontology.
Turrla albida
(Perry) most closely resembles the subspecies T. a
23
balten® is (Sowerby), which is most common in Lower
-Miocene and lower Middle Miocene deposits of the Caribbean area.
Turrleula eruzlana Olsson Is the type of the
cula, and represents the Lower Mionew genus Oruziturrl
cene element of a succession that ranges from Middle
Eocene to accent,
aanc.ellayla (Blvetlslla) sent jagensis
Marks was originally described from the basal /looene
Angostura
formation of northern coastal Ecuador.
It re-
sembles 0. charagota Olsson from Middle Miocene strata
south of Bahla in
KanabC Province,
differing from that
species mainly by having a slenderer body whorl, 9 Instead of IE spiral bands below the shoulder of the body
whorl, and a nearly straight columella instead of one
strongly curved toward the outer lip.
Tha two species
are apparently related, C. charspota possibly being the
descendant of C* sentiegensis, The ne« and the undoscribed species from the Subibaja formation are mainly
representatives of well-known Miocene genera.
forms are worthy of mention*
Marks, n. sp.
, represents
Certain
gamia ( Tamblornla ) keenae
a subgenus that Is known to
occur only in tower to Middle Miocene strata in California, and in the lowermost beds .{probably upper Lower
_ia
Miocene) of the Oatun formation of Panama.
Cancellarla
(Cancellarla) s.ursalta Marks is closely related to Q*
(£" ) dariena Conrad from tha Gatun formation. (This fact
24
was noted in th© paper by Marks (1949), p. 4.61.) Pltar
aff. P. thompsonl Harks, n. sp.
the species,
, is closely related
sensn stricto, which occurs in
to
the lower-
most (probably Lower Miocene) beds of the Gatun formation.
Clinura sp* probably represents the latest sur-
vival In Uaerica of the genus, which occurs In the
■
Eocene of California as "Hekewls t n ana* is supplanted
-
there by the Miocene to Hecent genus Megasurcula, Turri
*SiiS iSt£Silsl,il§,M
ai|bsp»
apparently is a somewhat
simpler
*
antecedent of the species sensu stricto,
, * which
■*■
occurs in younger formations*
,i|,»ip.,p,nppp.
p.p».^
p.P»,p,»»
j,
v..-rp,~n,j»i.pp
SccjjaJUgp sp. elosoly re-
sembles Sconsla laov.lgata (Sowerby), a Middle Miocene
guide fossil for the Caribbean region.
The range of spteles in the Progreso Basin is
shown in figure 7,
apparent.
A distinct succession of species is
Of the Si species in the type Subibaja forma-
tion, only five carry over into the superjacent
formation.
Progreso
Of the six species noted, in lbs aaiba member
of the Subibaja formation, only two carry over into the
superjacent
zacacb£a member
(the member contact is at
630 feet in the Zacachun corehole— between 2-560 and
£-710 on the chart, figure 7}* These facts, strongly
supported by the llthic character of the sedimentary
rocks, e.Te evidence of the influence of facias on assemblages of mollusks, and cannot bo considered as a good
basis for zoning the strata.
Nuculana sublbajana Marks,
«d
I
I
:
4
O
«0
S*
J
H'
o
4 ?■
©
H
gj
St.
rv.
X!
ill
y
tO!
lO] ©";
H] H:
H
nJ*8 m
it
4
H
H|
o
o>j
;
ai
rO
o
O
c ©
*H ,$3 H
.P H
*ljft
PM
o 4? m
v
m
«Oi
-Hi
2
m
401
Jm
aMW
V
*%rSJ
"^1
otj
h;
HI
Hj
Hi
1
1
HI
Oil
>9J
I
I
3KI I
it
t
—
I
c
4m
c,
-*4»4i .
# ■ml
©I
i
I
11
l>
*** 3
o
:: to!
9■wn
. m.l
j| || p o
w
j
Stw'l
.o>l
Ofc
j
me
m
H
m*
a>\
H
« in
<
■
j
g>
IS
I 1
c *h|
i
4Oi
H
1
P
P3
lvi
V*
tOi
Hi
(Pj
"
O
O <M gf
if
c c iMi
c#«
*
»$*
#
c
c
£S
4*
a
»
*
© *»
o
AH
#
4> ii
S &O *t
t*
SMS
■i
GO
H
*
»*
©>
m
m
X
m
D
c a <*
4d
454
*
4© 11 £*
P IS if ■
H
C? PI
is IS ©
«@
§ «
Hi£ i
*
©
I* ai
4* «& <rt
#
f
si;
ft
S 4*l %-4
13
ss ► «
lot!
in
m
«8 H
<**
ja H
U* # H
a
tit
g
o ®
f* 12
20*4
s%"
R
®
litM
UM
I1
Ht
#"-%
H *rf **t
IS
© ©
ci]
;
&
O'gf
SOj «
H
HI
"co
<o
oil
fit
-
is ♥»*»
oc
h
tr;
JO:
llI|
|
-<■■
*
ilI
3\
w
£*$
H
■p
is p
# I* ©
OH
i
m
«A
<*»
H
«**Hw
©
m
mom
ci]
I
1
!
H
"AM*
O-
IK?
o
O
OWI
c
m
*
1
o
m
£--
0,
@
*
IB
®
©
4*
-**
©
1..
I
&4
ft:
7«.
*
25
n* sp.
, ranges
"throughout th®
Subibaja fovnatloa, aisd
aay bs aonsidared a marker fossil la tha Progreso Basin.
It reappears in youngar strata in tha £aul«
Basin, pra-
suis&bly frSftafta* of environmental conditions again favorable feu*
it. The five a^ociOo %hm% occur in both th©
subibaja and Spo&rsso
formations
consist of raprasanta-
tives of tao promlns&t and durable Tartiary groups, tha
Are ldas (with jtoetla giacnslli Harks*, n. sp* , and Anadara
thalla (Clsson) and tha fanaridas
thqajpspal Marks,
a* sp*
, Ohlong
(with
fltar
aff,
P*
."roplßo^a dplsksr, and
Pltar aassohmßaaais Marks , n. sp*).
Tha fauna! assemblage of tha subibaja formation
is not well raprassntsd In tha Paula Basin,
ransaa
Tha occur-
of Spaslas Samoa to th© .vrorreao and Daule Basins
a < g lane sablba flaga tferks,
ara shown in fifties 8. |
is tha only species fro® the £aiba (lower)
subibaja formation to appear in tha E;.ul
specisa from
the upper
in*
of tiia
Three
part of tha upper (Sacschun)
bar also occur In the Baule formation*
Ana^yra thalla Dlsaon and Chlono
found also in th©
vyyEer
n, sp.
:*rot':rsro
mam-
Two of those,
MEyEJ'y
"
sr >
&Tm
formation Four long-ranging
apaolaa of tha northern sector of tha subibaja formation
era found in tha Pauls formation* la a|l, eight species,
or VBs of tha subibaja assemblage, occur in tha Baule
Baein.
Tha figures are showa in figure 6.
Bsoauss of
,
26
the small percentage of species in common, the patently
durable type of those Species, and tha relative stratigraphic position of tha formations, tha subibaja forma-
tion is considered not to be the correlative of tha Daule
forMation*
Since tha uppermost bods of the subibaja forma-
tion are similar both in lithology and type of fauna to
*
strata of the "Blue siitatone1 member of the Baule forma-
flam i the lack of correlation cannot b© dismissed on the
basis of facias alone*
3
basis for the correlation of the Subibaja for-
mation is given in figure 10, and in tha figures on percentagea of
species in figure 6.
ft* closest comparison
la with the lower 2orritos formation of northwastern fern,
with eight species {i3y»J in common*
fhese eight species
include such complex forma as
(Olsson)
, Terebra ulloa Olsson,
Hodson, and Chorus
MMiSM
S£Bl4ftM
Turritella hubbardl
(Olsson), Four distinctive
Subibaja species ale© occur In the Angostura formation of
northwestern Beuador*
since the Angostura assemblage is
incompletely Known, more species may exist in common. The
occurrence of a species of the peieeypoft subgenus Temblornla in both the Subibaja and the lowermost Gatifa formation, as well a©
n, sp*
, suggest
the record of
that th©
HJar
lowermmst
thompsonl Harks,
(3a tun
relative with the upper Subibaja strata*
correlation chart is shown in figure 11,
beds may be cor4 generalised
27
The age of the Subibaja formation is early Miocene,
approximately equivalent to tha Burdlgalian stage of the
European sequence.
This determination la baaed on a com-
parison of tha Bubibsja fauna with other kouth and Cen-
tral American molluaean assemblages, and on the local
stratigramla succession. Two species of the Subibaja
assemblage, Turris aljlda (Perry) and Ar ohltaotonl
ca
npbllis Hiding, or a proportion of
exist In the Recent fauna.
3.3fS
of the mollusks,
This figure is far below the
17 y stated by Lyell for the Miocene, and corresponds more
with his
3£#
for tha Eocene,
The discrepancy in percen-
tages need not be disturbing, because tha Subibaja species
were distinguished on a mora discriminatory basis than were
the Mioceno species determined by Besheyes and used by
Lyell,
In addition, moat of tha subibaja species were
denizens of shallow, near-shore
paters
susceptible to morphologic change.
aad, therefore,
Microps! eonto logics!
studies also indicate that the Subibaja formation is basal
Miocene (Stainforth (1948), p, 143), although the gentle,
facias-influenced change in microfauna! composition within
the Subibaja formation does not permit designation of the
Oligocene -.Miocene boundary on bioatratlgraphlc grounds*
Because of this weakness in the microfaunal composition
and the scarcity of molluscan fossils in the basal part
of the Subibaja
formation, the possibility exists that
these lower strata may be Late Oligocene (approximately
28
Aquitanian) age; however, it seems preferable and logi-
cal to include the entire 1800 feet of the type Subibaja
formation within tha Lower Miocene*
The ecology of the Subibaja molluaks was a normal
relationship between shal!ow~water marine organ!©ma and
the marginal areas of an Early Miocene embayment,
Hone
of the genera are .known to have occupied a strictly fresh
or brackish- water habitat, although fief ice, represented
by two species, often tolerated brackish
water,
Rock-
clinging -organisms, such as the limpets, Tegula, Thais,
Aeanthine, and Cerlthldeeu all of which live in the 111-
toral zone of the iscuadoraan coaat today, are missing*
* The
-i
were noted living on rocks be
the Ecuadorsan coaat?
along
tween tide levels
(Gray),
Acanthina brevidentata
Anachls rugose
'
following species
TlowerSyT»"^nac£|s
dOßtes aultlfo'riSs
fluctuate (fliwerbyl,"iSracliy-
1Carpenter),
cantharus gw»
sa*
irithTdea
eusti
la vire-
lanaxis
fiipibnyx
da-
planip
"reticulata
.
. Thais
mm***m*-**m<mmi
c)
w»u«m» mgm
triangularis { Main"pp*
** mmmmmm******** *m mm
Asaphls
mm*,
mmm*
** mmmmmm ****m -mm.m** mm* m.mmm* mm
{yoatoanachls)
******** m
"*■
** .mm*************
ste.yenso.ni Marks, n* ap* f is sub-
generically distinct from the two species of Anachls now
found living in the littoral gone; and Chorus eruzlana
(Olsson), formerly considered a subgenus of Aoanthlna.
29
is quite distinct from the Hecent rock-dweller, Acaatfalna
breyidentata (Gray),
Of the living species represented in the Subibaja
formation, Architectonica nobills Ending and Turris albida
(&®TTy) both inhabit sandy mud bottoms of little depth*
Cay.lluclns chrysostoma {Phllippi), which cloeely resem-
bles £*
sechura (Oleson) has been taken
depths and
*
waters" (Smith
,f
*** in moderate
upon tidal flats of bays and protected
(1946), p. 48)*
Cancellaria reticulata
Linne, type of the genus and subgenus to which belongs
C aur salts Merks,* has been taken from waters three to
mmm.
,*»
*m**,mo**m.*!mis*mmm<.m*mm*
six fathoms deep off the coaet of Florida (Perry (1940),
p, 173}* Nuculana (Saccella) calllmene (Ball), which
differs little from M.
{§*)
sublbajana. Harks, n, sp*
,
was first collected from mid at a depth of 259 fathoms
in the Gulf of Panama, and later at a depth of 100
fathoms In the Gulf of Kicoya (Hertlein and Strong (1940),
P*
Telllna (Burytelllna) sinulane
which resembles T.
sp*
C, B,
Adams,
b, hae been dredged from mud and
sand at a depth of 8-13 fathoms off the coast of Mexico
and Central America (og. cit* (1949), p* ?9), Chione
(Chlonopsla) amathusia (Phllippi), to which 0* (£. ) £roplnQ.ua spieker may be compared, has been dredged from
mud and sandy mud at a depth of 13*41 fathoms at various
stations off the coast of Central .America (op. cit. (1948),
p. 183).
30
The remaining. species of the subibaja formation
represent groups of varied habitat, or for which environ-
mental data
not known*
All of them may have existed
in the depth range suggested by the species noted above,
or from three to about sixty-one fathoms*
Tne lowermast
strata of the daiba member, in which only nuculana
salbana JJarks, n, sp. is found, probably were deposited
in somewhat
deeper waters*
All of the genera represented in the Subibaja formation, with the exceptions of Luolnomat m& Qtvw^DjjaomM*
have been previously noted is Hecent or fossil assemblages from tropical regions*
Ho similar assemblage has
been ascribed to a temperate or cold region*
Luelnoma?
ap. la present only as a single poorly preserved specimen.
gtroaibi.conus is a new genus and need only be added to the
list of predominantly tropical
Summary
genera*
of paleonto lonics! data,
The Subibaja
formation la of Lower Miocene strstlgrapbio position mM
may correspond approximately to the Burdigallan stage of
the European sequence*
It correlates moat closely with
the Lower Zorritos formation (Lower Miocene) of Peru, and
also with the younger part of the Angostura formation of
northwestern Ecuador.
It is not equivalent to any of the
exposed strata of the Baule Basin.
The lower part of the
Salba (lower) member was probably deposited In tropical,
31
marine waters deeper than 60 fathoms, whereas the remainder of the formation was deposited in water between 3
mm
60 fathoms In depth and far enough from shore so that
littoral (between-tldes) organisms did not reach the deposits.
PROGRESOFORMATIONOFTHPEROGRESOBASIN
Geologic data*
The progreso formation is named
for the tola of x-rogreso (formerly celled sen 2ob& de
Amen), which lies 53 kilometers went
south of Guayaquil,
ana
£4 kilometers
The type section extends from the
railroad station, I*3 kilometers south of the town, for
-
a distance of 11* 2 kilometers south along the Progreso
Playae highway,
This section was first mentioned by
Olsson (1931, p* B4) and later by ahsppard (1*37, p. 134).
strata of the same formation lis under the type section,
are exposed in railroad cuts east of Progreso, and were
penetrated by the exploratory wall, Quijano-l, which is
10 kilometers eaat of the town.
Approximately 4970 feet
of strata are exposed in the type section, ani 3905
tional feet in the
of 8875 feet.
subjacent beds,
addi-
or a total thickness
The formation Ilea at the surface of the
entire central portion of the Progreso Basin, eowaring
an area of about 1000 square kilometers.
*Bie llthology
of the formation is varied and indicates deposition in
shallow water.
A generalised description
follows!
32
Progreso formations clay, ©ilty, green;
sandstone, softTliilty; arid silty shale; with
local accumulations of bsntonits, bentonltle
shale, tuff, pebbly sandstone, oyster-rich
sandstone with durable calcareous cement, and
fine conglomerate, Carbonaceous matter rare.
Calcium carbonate prominent only in accumulations of shells* Bedding obscure* Strata
variable in thickness and of short lateral
extent* The base* in the vicinity of Zacachun,
marked by a sandstone unit about 300' feet thick.
ftiegafosslls scattered at many stratigraphlo
levels, mlcrofosslls rare*
The topographic features, where the Progreso formation crops out, are of moderate relief. Typical Progreso land forme are shown in tha photograph, figure 2,
taken just west of the town of .Progreso,
Low, fairly
rugged hills en^ rldgss, narrow valleys, and a heavy
growth of vegetation
are predominant.
The vegetation
is dense, of a seal -arid' type, consisting mostly of a
tangled undergrowth about ten feet high, with local
con-
centrations of large trees, especially tiie kapok-bearing
ceibo, in favorable situations*
£00 feet.
Belief seldom exceeds
The basal ssndstons near
&aeaeht£n forma an
elongate ridge with a maximum relief of about £00
and a length of nearly 14 kilometers*
feet
It is probably
the moat persistent lithologic unit in the formation.
The attitudes of the Progreso strata are variable.
The basal beds near Zacachun dip gently eastward.
The
beds near the center of the basin vary from inclinations
of aa much
apparent*
a®
13°
to flat, and several weak folds are
33
conditions of deposition were those of shallow
marine and brackish mater,
Mud-flats (indicated by aun-
cracksd, ripple-aarked, silty clays), local hiatuses
(seen In local disconforruities)
reefsI'} existed*
, and
sand lenses ("oyster-
The lithologic evidence for shallow-water
origin is supportsd both by studies of the foraminlfers
(Xhalmann,(l946), p. 1B36; stainforth (1948), p* 143),
and by the paleoeeology of the mo Husks noted in subsequent paragraphs*
Paleontology.
mmm* mmmmmmmtmimmmmmmmmmmmem*
lorty-one species of molluska from
m
-*»
the Progreso formation are analysed in this report*
Their
ranges and order of occurrence arc shown on the chart,
f' 4 r>-\^v*m c
Twenty-four of the Progreso specie* have been de-
scribed previously, iwenty-one of tbeee published species
occur in other regions, and these occurrences are shown
In
figure 10.
Their stratigraphio ranges may be sum-
marized as follows?
----
Lower Miocene (of Peru)
Lower to Middle Kiocene
Lower to "Upper Miocene
Middle Miocene only
IEMls to Upper Miocene
Middle Miocene to Pliocene
Middle Miocene to Beceat
-
4 species
n
6
-i
2
«
6
1
1
1
>t
Some of the previously described species are of strati-
graphic interest.
Both Anadara thalla (Olsson) and Conus
sophus 01aeon occur in the lowermost beds of the Progreso
formation, and in Peru are known only from the Lower
34
formation (Lower Miocene).
Spieker has been compared with P.
Potamldes infrallretue
.sMEEfBMSJM
originally described from the Dominican Republic (Bedberg (1937), p. BG24)*
In Venezuela the species occurs
in strata close to the
boundary between the Lower and
Middle Miocene. Jectsn plurinominis Pilsbry and Johnson,
P,
of which mm-
p*
mmm-
progresoensls
..- Marks is a new subspecies,*
<Sl»i
*m
mtmi
haa representatives not only in th© Lower and Middle
Miocene strata of Santo Domingo, but also in the formations of Middle
suela*
Oligocene
to Middle Miocene age in Vena
Here it is known aa Facten buchiyacoanus P. and
li* Hodson and subspecies
E* 1* felconensls
{> b. m^racaibenais Hodson and
Hodson.
Turritells altilira Conrad
Is represented by numerous individuals*
Here, as
in
Colombia, Panama, ent Venezuela, It flourished during
Middle Miocene
time,
Turritella abrunta Spieker, the
largest of the Miocene Turri tsllas, furnishes a connect-
ing link with the Middle Miocene strata of J:btu (Upper
and Cardalitos formations).
In Colombia, the
closely allied form, T, abrupt*, fredeal Hodson, la found
in the lower beds (H-B) of the
falsi**' group,
which my
be upper Lower Miocene, aa well as in much younger Mio-
cene strata. In Venezuela,
T,
a. fredeal Hodson occurs
in the Middle and Wpper Miocene, In Trinidad, the very
similar T*
abrupta
trinitaria Maury la known to occur
only in the Upper Miocene Springsle formation.
The
—^—
—
'■''
i
©— TO—
—
*
—
£
k?
j
g_
—
——
3
p
©
■
m—
TO jc4
TO H-
f°
**
HW M»3©
OTO
*TO Br-to
Q ■» l*W l*ft O
4 coH3
o 4 o >*
o"^ w
«< H- C *T3 W
♥* H © W" © tJ © »<
fo-o ©-g-y
TO H TO r-x
3 09
& H- © O
©
CO OH
©
c+ OJ TO 3
JDH.W
-*g
©&a*«►?
"5 s^-n
r
»
TO to TO
»^ ©
%7
: _i_c9__o_
to 3 *s'|
J
p. to
3
>:<
. j .
,
J
+-4- -44
4-
~
r
I
~i
H
i .
:
_4
i—
■Hr -f
v
■f--4
—\
——
t
——
t
x-x— ;x x ;i
i
ao
*f
if
a
-i.
1
1
——
—
;■
;■
T— ,
4" -4-4
4
x
ja4-—
fc.
i
— t
|
r~r-
h— r-
-
Tt-r
X X —
r
f
XX
"
i:
I
-M-ITI
x-x—
jx
"
■
■
'
-4- .1
-i
©
4»O
*^HP
" !
■
>,,4
If.
IPSf ?s
'
— 4- T
44—4x
4--4-4—
fat
TO TO
H TO
o TO
- 3
o
p
O
o
_&Co
o
""§"
o
\
a
(3)
R
;>
4- -i
Co
M
3 .
TO
; -f—
.
O
!
1
-I
X X
■-!'"' i.;ft!
—
i
TO
ITI
x
—-
-i
If H—
T
;
"■"■!
co
© *J
—x x
H
LU.
CO
H
H
SLJIL
r— l- TTT TTT
xx
r Cn
B
TO>3
i
i__4-
«
3
cr
I©
~H-^
©
r—
4_
-l-
T
0-jcj
to to
HTJ
O j©
TO H
-t-
i
coJ L
r*
-4—4-4—
-f~iH~i
—
-jx :xxx
—_J
— r—
I— .
I
4
XX X X X X X X
j
— j— —
I—t1
8O
—4- L±
;
:
;
h
n
CO
-4-
i
XX X X
—
—
————
— — ~\
r
i
?
J
—.
+
"
;
3
I
i
——
L_L_
4— i
1~
■
H-—
>*:
4-
fcH
H-4 ~r T-r
i
—
\
re —^
4-
TO
- TJ — I—
TT^--+S-^—
25". » .5
—
d
£
AOiW go- H
W
H" OD- O S
w
© H M»X 3
>tJ
QQiWPr< N
N oas_L_
-*<
—
J.
j
»-"■££-
-gyp
b^>J. TO
-1
---
TO
g-
■
—
©
©
C3
ho
*2_
o.h«oo ho©
a o to
-t*-ri-rt— <*^^» tcJ- Ht£
H■-♥-*
■■■«■
x+ H*3
"
O O 3 TO
CO©©
3 TO
O © 3*
&
3 H Hp, ;3 »tf *> £
H»
3
3
M£H^Og. © TO g
H .H- l gH»H j^
PH-OrQWo;
Cto4 Oft
3
-t-
I
TO
_
o
c»
7g
*j
to © -o h- » o
3*
£M
o*T^
£ 2 £* £
pP^WJ^pTt®^^
©*+©<+<+
TO ■»rt--©-»»0
©
©■©«!»"*<<&
p
H*
_—
O-htJ
O
■sit
.
O- >" O► &5
WtU M-O
o hh ?p g
feJrt3 o o h- o3
3 © »i "**
**3- ■"■**a4*S
3 ci- 3 o
-3 o
►* o
►* £ p
— I
■w
r~
-r-
—
-1
I_H
,
35
subspecies T* a, trinitaria Maury la not identical with
T. a. fredeai, as stated by ¥©kes
differs from it
by being
(1938, p. Ed), but
somewhat slenderer and by
having two fine f spiral cords on the anterior slope
glemontie daxlena (Conrad) from
instead of only one.
the Progreao and Baule formations is identical with example©
from the Gatun formation of Pansma, especially
in ita large
size,
Anatlna IRests) undulata |Oould)
has not previously been noted in beds older than the
upper part of the
Tuberdf
formation
(horizon
P) of Colum-
bia en^ the upper part of the Urumaco formation, upper
Middle Miocene, of Venezuela. Turritella infracarinata
Grzybowski is locally abundant, and forms a connecting
link between the Middle Miocene beds of Peru
to
the
south and those of the iuaule Basin to the north*
Seven of the .Progres© species are herein described
as new.
Three of them, Hostla. macnelll, Pitsjp aff. V*
thompsonl Marks,' n* sp* *t and mmm-mmm/m*
Pitar zacachunenels,*
_"
mm*mm~--mJmmm.\Kiimm.mi
mmmmmim.mmmmM.Tmmmmmrtfm
-„.*■>,
are
found in the basal Progreso strata and also in the upper
part of the aublbaja formation.
Anodontia stainforthl
represents the first recognition of the genua Anodontia
in tropical America, and is remarkably similar to 4*
globulosa
(Deshaysa) from the
lian atrata of France*
%ultanian
and Burdlga-
Megapitaria Clascal is the first
species of Megapitaria noted in tropical American Tertiary strata*
It is most similar to the living west
36
coast species
C^owerby) and U* agualida
ft* aurantiaoa
.
(% So
mr werbf
v)*
t
■
The local atratigraphic ranges of the mo Husks
of the Progreso formation are .shown in figure ?. A dis
tinct fauna! sequence is apparent.
A lower group of
strata la marked by the extinction of leetla macnelll
Marks, n* ap«
m
?
, Fltar
w
wMm**mm<mmmm
■#**■*****)*#* <m*t.mm-*m*m<.■■
Anadsrs thalla (Olsson), and
n* sp, |restricted to
*—
■"*
c^» it* ®^olo^a
Fa aclplariat
,
P, thompsonl Marks,* n, sp.
*
aff. ***"■
m
':>mm»
£itar zacachunen.ils Marks,
'*"
this lower group
are &ectrello&a
yF
*^'vm><m'imm'imimm'.m*m^p*^mrm^^mm»mA*'-
(Gray), Cp,nus, cf. 0. bravol spieker,
&p*
, EoMmMee
sophus Olsson, Ostrea. sp*
infraliratus Spieker , Conup
a, and Ostrea
b.; appear*
sp*
lag for the first time in this group are
Mfio£Sa\ias
ecuadoriale (Olsson), Me^apltaria elsaoal Harks, n.
ahd Mactra irldia Olsson*
liagajgi tarla olssoni,
* and
»„ ,.- ,-,„,.„ ,-.„,.
*mm*mm**mmm**m*mmmmmm*m
,|»..P...«I
is the complete range of Feeten plurinominis
by the last
,
in Intermediate group of strata
contains the last occurrence of
sis Marks, n* subsp.
sp*
proeresoan*
An upper group of strata is marked
occurrences of 2? species, a criterion, how-
ever, that la not blostratigraphleally useful, because
the superjacent strata are missing.
In this upper group,
24 species begin, a phenomenon that mmy be attributed to
tha chance accumulation of numerous specimens in a few
favored localities, Banging through all three groups of
the strata are four species; Turritslis gatunensis Conrad,
Chione jpropln&ua spieker, Dinpcardlum ecuadoriale (Olsson),
37
®
n® Mactra irldia Olsson. Three additional spenies that
were previously noted In the Subibaja formation of the
Las J&a&a
and Carrlzal aectora of tha Progreso Basin may
also be included hares Doainla delleatiaaima Brown and
Pilsbry, dementia dariena (Conrad), and Chorus cruziana
V Olsson)*
In spite of the apparent sequence of faunulas,
Molluacan zonea are not here set up for the Progreso formation.
Too much of this apparent sequence is dependent
on lithic facias and chance findings of fosslliferous
strata*
The Progreso formation sequence of species is not
the same as that of the Baule formation*
Comparison of
the ranges of the Paula species (shown in figure 9) with
those of the .Progreso species shows few similarities. The
species that
are common to both basins are shown on figure
8, following this page.
formation^ 30$ of
(figure 0).
Twelve species of the Progreso
the total, occur in the Baule formation
Anadara thalla lOleaon) and
Po^mides infra-
liratus apieker ere restricted to the lower part of both
formations; Mnooardlum sftuadprlals (.Olsaon) occurs in
the basal and uppermost beds of both forma tions; and Tur-
ritella altilira Conrad and Turritella Infracarinata
Grzybowski occur in the upper part of both formations*
These are the only species with comparable ranges in
38
both formations, although further collecting may reveal
many more,
pinooardjum ecuadorials (Olsson) Is a marker
foasll for the entire irogreao and Daule Middle Miocene.
Anadara thalla (Olsson) and rotamldes Infraliratus
tfpieker may mark a lower biostratigraphie division of
the formations, and Turritella altilira Conrad, fuSrl-
iSii® Infracarinata.
Grzybowski, and Turritells abrupta
Spieker an upper biostratigraphic division.
The Progreso formation sequence of species is
roughly parallel to that of the £©rritos
western ireru.
group in north-
The highest proportion of Progreso species,
BZ$, ooeurs in tha Wppes? Zorritoa formation (figure 6).
The lowermost 100 feet of strata contain 16 species, of
which three are restricted to the Lower &orritos formation and
on©
to the Variegated beds*
The remaining
thousands of feet contain £9 species, of which only
Chione propln9.ua, iipiek ar is restricted to the Lower
£orritos
and five are restricted to those strata called
Variegated beds, tipper lorritoe, and Cardalitos.
The
respective proportions of mutual occurrences are shown
In figure 6, and the species in figure 10*
The ecology of the Progreso moHusks was a relationship between marine and brackish-water organisms and
a silty, shallow-water environment.
strata of the
Tha lowermost sandy
formation contain a few of the shallow-water
39
marine mollusks of the Subibaja formation, such as Noetia
macnelll Marks, n. sp. , 11tar aff. P. thompsonl Marks,
n'
SP*
* Pitar zacachunensis Marks, n. sp. , Anadara thalla
(Olsson) , and Chione propingi3.ua Spieker.
In the same basal
lithic unit appear for the first time Ostrea (Crassoa tree)
spp. and Potamides infraliratus Spieker, both considered
to be indicators of shallow, brackish water. Melongena
sp.
, in the basal bed, may
also indicate brackish water,
as does tiie Recent Melongena melongena (Linne).
Higher
in the formation, barren, silty clays and silty sandstones
alternate with poorly sorted beds that carry fossils of
genera which now inhabit normally saline waters. Locality
5£9, for example, contains specimens of Turritella, Clemen
tia, Dosinla, Architectonica, Chione (Llrophora) , and
Panope, a nominally marine assemblage.
locality 508, with
19 identified species, has an assemblage that might be com
pared generically with a collection from the Ecuadorean
coast today.
In general, most of the Progreso molluscan
species indicate a shallow marine habitat.
That normally
marine situations alternated with brackish water situa-
tions during Middle Miocene time is suggested by the
sporadic occurrences of Ostrea (Crassostrea) fragments
throughout the formation, and by the lithic character of
many of the
strata.
Tha genera are essentially tropical.
Summary of Pa lepntp logical data.
The molluscan
species indicate that the Progreso formation is of Middle
Miocene age.
The formation Is the correlative of the
40
Daule formation of the Daule Basin and of the lariegatei
beds, Upper 2orritos, ani Serial!toe formations of north-
western Perm*
ft* genera represented in the £rogrea»
strata are shallow*water types,
ana
they suggest normally
saline water alternating with bracMah water in a tropi*
esl ellnate*
The
i _c
the
DauleFormatioTnHBDafEusilne
loglp iata. The Daule f-r:attcn is
.*ule BLfcJn.
vrt ed
for
Th- t:,y-e section, here designated, is
exceed nest of the vill"/^ of *kan;ralife, which is
$4
feiloaatara north a»4 41 kilometers wast of Guayaquil*
type section extents from locality I.P.C* 14S&, 8.0
Th®
kilometers B ?■# '# of lersaalia, to looality. 2.P.C. MMf
.20,5
kilometers S S30 fof Jerusalem, a linear distance
of !Z*m feiloaeters*
Locality X.P«€*
MM is within the
lower i"Basal eelearsaus*} wiaber of the formation, uni
aper
locality 1451 is near or at th© a..osia top
i^Ugp^r calcareous**} meiaber of th©
formation*
line aiitstone*} aenber ilea between
then,
ti« mldile
The asset
thicknesses of the for.a«atlo« have not beam measured ao«*
ouratelf in this .section because of local structural eon*
plaxltlaa and obaoure stmtifieatlaa.
the "Basal ealoara*
;
member, measured in the aio lanehal t about IS ttilo.meters norlhweat of th© type see lion, is 1640 feet tMete*
om® n
The ?tfilue slltsto&e*1 mmmb^T in the Tlcinity of Jerusalem
is estimated to be about 600 feet thick. The
41
oaloareoua^ member la at least several hundred feet
thieic, and Is being eroded*
The **Sasal caloarsoue*
member la mainly calcareonaly indurate! sandstone, the
**Blue siltstonew is a topogracftleally reeessiire siltatone, and the *npper salesrooms* sasmbar forms cliffs
of ealoareously indurated sandstone.
The names glTren
the meiabers are field terms! data sufficient for naming
the members properly and designating their type stations
are not available.
The topographic expression of the
Baule formation is fairly rugged, with hills several
hundred feet high being deeply incised by the eastwardinclined drainage pattern.
Vegetation ranges from tall,
dry brush and scattered trees to
near rain-forest, is
which coffee and cacao plantations thrive,
fte town of
Pedro Pablo Gomes, ifeleli la Moated on exposures of the
ealoareoms* member* is shown in thm photograph,
figure Mm the Baule formation aropa out over meat of
mm
wester®
portion of
am
Baule Main, and it probably
ilea bammith the younger continental strata that cover
the eastern portion* Tfee dip of the basal Baule beds at
%tmtw western margin is toward the east,
aiserepaaelaa
, probably
caused,
although looal
by fault ing» are
e©mso.»,
Toward the center of the basin* the degree of inclination
embaydeoreaaes. The Baule formation was deposited in an
meat of the Wmttt®
Qmmm that epamei to the north mat
terminated to the southeast less than 40 kilometers frost
42
auayagull.
The basal strata lap over Igneous and mata-
morphia reoka of Cretaceous age along the western margin,
but probably lie ooneordantiy on older Tertiary strata in
the oentral portion of the basin*
Forty-four speeiea of serine soi-
Paleontology*
lness froa the Baule formation were Identified*
They
are
listed in figure 9.
Twenty-four of the 44 Daule apeeiea are already
reoorded In the literature.
These 14 apeoiea alaarly
ilea to correlation of the Baule
formation with Middle
Miooene formations of the Panamlo region, with the
r-ro-
grese formation, and with the Middle Miocene formations
of northwestern J?#ru.
The Paula fauna coaatltutee the
oonneetlng link between the Kiddie Hleeaae assemblage*
fteamie region and those of Peru and the irogreso
"
msiu* Hi® mutual oeenrreaeee are shown in figure 10
Sight of the published Baule species oeour in the
of the
OatA formation of fan-suet
sroMtectpnlea
eorusoa olssen
Ming
;-rown and Pllsbry
Arc;
rltelWaltlTira Conrad
iena. f coarse)
SleaSfnTHTc
]3t3»csf£x
nisi??
na fouia
Seven of the published Mule apeelea oeour in the
upper Tubers formation of Colombia ("sMMtf1 P-B of Anderson, 1929}$
43
t^ietoarj
Arc^hlteo^nljoa nobllls Hiding
555i|nl^4el.lcatlssTS*"bro wn and Pilsbry
Eaarssaa tells
berry1
Turritella altTTlra^Oonrad
ileaestia dariena { Conrad)
."* rnSsto- , raba.nl d'aury)
4a ties gtfgsgm
Toula
live of the published Baule
ape©
las occur in the
Cucnrrnpi beds of western Colombia that have been de*
scribed fey Olnoalfea&et
tectonica nobill s . ac lag
.nrad
aala
ffiai
* 35so
gy \
M^aria
. enais Qiaoaikado (of.)
Perebra c
x c u\
rfaXliaiiillX;-
.."
"
Slaven of the published Baule apeeles ooour in
the Middle Miooese formations of Paru**the Variagatei,
ipper Zorritoa, and C&rdailteat
Doainla delicstiaslsa Brown and Pilsbry
Liratus Spieker
v lexer
fSvSSStS InfrßTiratus
C lament ia larieS**Tconrad }
la^altlllra Conrai
"arinata Grzybossfci
furiTtelH 1
"bravol sprier
1a tm ieishore
:qm cj
c SFuscs Olsson
AxcHtgctonTca foxllilaaris (Kelson)
Sln^cardlm'^cuilor^^ I i^on)
:jjm of, j?7 co-
insis C3*orfeigny|
Eleven published and one new species are eossMSi
to the - ITogreso and Daule formations. These are shown
in
figure 8.
On the basis of the Baule species known to date,
the most reasonable correlation of the Caul©
formation
is, therefore, with the Gatun formation of Panaaa, the
upper Progreso formation of southwestern Kcmsdor, the
44
upper Tubera foration and the Cucurrupi beds of Colorn-
bia, and the
ifltoup of Peruvian
formations sailed far la
<
gated beds, upper Eorritoe* and Cardalitos.
Thmtm eor<
relations are ahowm in figure 11.
Bia paleogeographle significance of the Baule
asseiablsgs is shown by the feet that it includes ten.
spoolas previously resorded only froa south of Ecuador,
eight speeles previously recorded only from north of
Ecuador, and six species recorded from both north and
south of louador.
ft* .Progreso formation, in contrast,
includes eleven spooiea previously recorded only from
south of Ecuador, two apeciea previously recorded only
from north of Ecuador, and seven speoies recorded from
both north and south of tenaior*
Jtlgfet of the
Haale speetea eeeur in the lower
Zorritos foration. Lower Monona* of Pern*
these also oeenr in overlying strata in Perm.
f&ree of
Of the
remaining five, Chione proplno^ua Spieker ocours also in
the Ifrotivem formation.,
raj;,;in*;
well up in the section;
and Sucre asatelle berryl {Spieker3 ooours also in the
u^per Tuber £
formation, Middle Mooese, of Colombia*.
Three sfeciea, snadara thalla. fOlssom}, Conns sophus
T/isson, and Turritelle prenuncla Spieker are thus re-
striated to Lower Miocene strata in WmtM* but occur in
Middle Miocene strata In "Ecuador,
saadara thalla fOlaaom}
45
"u*^
s£sMi ®S2feM Olsson also occur
in the basal beds of
the Progreso formation.
Stratigraphicslly, the most Important speoies of
the Baule formation are probably glnooar^ium eeuadorials
r
(Olsson), which also
Eorritos forma tions|
occurs in the Progreso and the Vppex
£etaaides infraliratus
Spieker,
which occurs widely near the base of the Middle Miocene;
Hatlea
guppyana. Toula, which is also found in the Panama-
nian Gatun formation; Conus multiliratus BUse of the Mcxi
can Miocene; fyrritella lafraearlnaja Grsybowskl of the
Progreso formation and the Middle Mlooen©
of Peru; Pitar
(Ball) of the Gatun formation;
Tfeltlarla
wxleana BSae of the Cueurrupl formation, Colom-
bia, and the Miocene of ? :exieo; and Panope cf*
E* ££SEils~
bensi a (d f Orbig«y), which occurs high in the Progreso for-
mation, In the uppermost Middle and the Upper iiioeene of
I?eTU, and perhaps in the Pliocene Coqulsibo formation of
Chile.
The new species found in the Daule formation belong to well-known Tertiary genera.
The oocurren.ee of
*" , la an extension of
¥i tularin aeuedorana Harks,' n. sp..
..in'
UMiiipp- »>i,<hi~..~^pp.»
mam..,i --.,^.~e»w^,ppp»«l,li,in»ij!l«l|p>»»
the range of a genua that was not previously known from
strata older than Pliocene*
Bona of th© other genere
represented by new species are restricted to the Middle
Miocene, nor are unknown in the Middle Kloeene deposits
of other regions*
46
The Baule speeiea oeetar in a fairly well-ordered
sequence, with five -species restricted to the wlasai
calcareous* member, 25 restricted to the * ßlue siltstone w
f
member, and two restricted to the ''Upper ealeareousn
seia-
However, this mppevant sequence is not sufficiently
bar*
reliable to allow sanation, as has bees shown by eomparl*
aon with the Progreso Basin aeejuence, and as can be demonsirsted by noting occurrences of the BmwJ** spaeies in
other regions.
The fact that only one eaMplete saotion
through the Baule formation has been sampled thus far
also
suggests that sonlng the
would be premature*
Daule for sat ion at present
nonetheless, certain beds seem to be
mrkei by distinctive assemblages that
stay,
upon later
chocking, prove to be of stratigraphic value.
4 "lower .group of strata is ..arkad by the occur-
colombifn;si§ (Weiaberd), Melomega
rences of
colombiana ieisbord, Glycygaerla
jyyratuji Spieker.
sp*
t
and rotaMldes
iMSE*
According to tha evidence now available,
these species may represent a restricted lower ri<a ie
Miocene assemblage*
a* sp*
.
The striking
ciaulseaa Marks,
is prominent in this ease Lblege., but o coup lea a
higher position In the Ifeogreso Basin.
.4
middle group of strata is characterized by the
oeeurreMte of the following species?
Terebra cf * T* cucuryupiensl
.a Oinomikado
fri¥seHTl-Srks
Cancellable
47
sSH&Sypus predlstortus
n. sp-#
..phostoaa. sp/
oatbina dauleehlca Iferka, n* sp*
ix
an *
. aff p* zacachunenaia Harks, n* sp
Cane c■"11;.'/' i \ eaUealva Harks
.
„i i
so*
pis
fltiy
.
klliiMill®
pTtir
According
rana Harks* n» sp*
J&
A
f &" ap.
'/j _ ytV Ulceus I'^ail)
to the iv 3i -a
ave! lIIs, this
n©
i
of It species say be restricted to strata that are approxl
tely niddle 1 iddle 1 lei me in age,
An upper
.group of strata is represented by the
ucurrunce of ustrea
related to 0.
y
op,
y
fhis
f-tajaala bower by, nay prove to bs of re
stricted range, diagnostic of uppe
. i Kiocena strata*
of the ao Husks in
are shown in
fj
;-traa
.--a,, isx
Daule formation
re 9*
ffca sequence of species is not parallel to that
of the Progreso formation, '.ilt.-o*.
about the same relative position*
cussed under ths
3?~38«
-
k.„.
i
-.©
*m©se species are dis-
iro r.i.o ferns tien
twelve Cauls f r -i&'nn
total,occur in the - -
*
species occupy
1501,:,p. i J,r,?
c'.js,
. formation*
or
£7.,
,
W
of ta,e
neidaring the
laogeograpblo relatione of ths %» format ions, this is
a evidence for c
a eeies cosae
irln tr»e» correlatives*
b formations are shown in f
Corr I:tior -I the Daule for ation
been considered in preceding paragraphia
generalised correlation chart.
■
,s lias
are 11 is
48
a normal relationship between marina organisms and a
shallow to moderately deep, normally saline environment.
Only in the "Basal calcareous" member are there species
that suggest brackish water
— Melongena Colombians
bord and iotamldea lnfrallratus spieker.
..eie-
i'ha sand con-
tent of much of this basal member, and the presence of
dementia dariena (Conrad), indicate that the member was
deposited in the upper neritlc zone, and probably within
a few
kilometers
of the shoreline.
Its stratigraphio
position above Cretaceous rocks on the margin of the
basin indicates that it was deposited during a transgressive overlap.
The 'Blue siltstone" member represents deposition
at a slightly greater depth,
huculana subl
banana Marks,
n. sp. (mentioned in paleontology of the oubibaja formation), may have lived in water deeper than 60 fathoms.
Most of the "Blue siltstone" species, however, are similar to species that now live at depths ranging from 3 to
60 f.-a thorns, or on mud banks that may be exposed at low
tide. ClfjMfttla dariena (Conrad), Architectonica nobllla
Koding, and Caviluclna thalmannl Marks, n. sp.
inhabited shallow water.
, probably
The three species of Turritella
probably indicate a habitat in the upper neritic zone
(Merrlam, 1941, pp. 14-16). Hundreds of individuals of
many species are fragile but well-preserved, indicating
49
iv;t
let*
bottom condition* were
est dees
StrOl i~l
}
W^sr<Jb
So
species
sere noted
t of the "Blue silt*
♥'
■v .-;" been ac-
ato&e" meaateeF, therefore, is helievisd
posited In normally saline ni- tor , at
;"y tj
toe-
*-
twees 3 and possibly ©0 fathom* under guiat conditions
tars from t
sevei
#s)
oer 1* sa»4j
-re 1careous*
s specimens of o&trea
*
sis.
..!rs
eoouSjdHiß
"JKS. e^
sp*
that may h' -c XiYed in shallow, near-shore
the %yaer calcareous"
tor*
I1 11ne *
.::r.ber t
therefore! is con-
eidered to rafraaamt a near-shore deposit.
;raphle position above the
n
hlm siitatons
it nay lava Haas laid down tinder eoaiitioa®
offlap, thereby
tar ...In-- ting a cycle of
Its strati-
*
8
suggest®
that
of regressive
-a
aie
marine deposition in tbe l-onle Basis*
Ssaaayy
of .pale
.gioal
data,
Tha sellmaaaa
species Indicate that the BaiAe formation is of Middle
Utecene
age*
the formation is the irrelative of the
3?ro t roso formation of the Progreso Basin, but was not
continuous aiih it. It also correlates with the forma
tlons on northwestern lertt teown as farlegated, Upper
rrito* t and Qardalito*.
A
correlation also exists
between the Daule and the Guaumpi beds and the upper
Tubers gromp Clones Jr'~B of as ©mob, Vs>-9) of Colombia,
and with the
Gatin format!**,
Panama*
Tha lower (
al
50
calcereoue") member waa deposited during a transgrssslve
overlap
on Cretaceous
.er|«
|
rocks; the
middle iwBlue ailtatafie")
vim .aters 3to 60 fathoias deep; fend
;.t,
dethe upper "IRper calcareous* suwsber as a near-shore
1
posit during
ara
.
live of flap.
51
Correlation and age
The Subibaja, iro^reso, and aaula formations are
considered to he of Miocene ay 5 l/e.-u-se of
i.
*r strati*
graphic position and the nature of their mollusc an fossils.
The ©nfeihaja fonation lies conformably on strata of Qlijgo*
cena &fi*» as has been shown by etudes of the foraalnifera
(Stalnfortb, 1948, p. 143}*
reso formation lias
concordantly on the Snbibaja foraatiom*
fhe Daula
foj
tion lies unconformably on Cretaceous rocks at tuo ma
-. . c
of the Daule Basin,
aoiiuseaa t ;;i-uiila
three
formations include species tbrt oesu? eleeebere only in
strata of aaaaptad
*fi 1 1
-^;»ne
age.
These epeeles are shown
:i$ .JM* #
■9 Lover 1 loceoe and
I
need in accordance with current usage areong
ists now working in Boat
ceno is oor.sl^ar©^
.-..
.-irn
j :"
.. >t*ric
tJ
to be abai-t the
toeene, are
C-"
';
*-.;
'a.y;ntola-
Lower
t; -;
io«#»
Bnriigallan Stage t ana: Midrie locene approximately
equivalent to %hm fIndonesian
tege,
va-es
Helvetian aaS
"
or the combined
.. sv 4 ienee for m*y_~
geating, tMese correlations is baaed on cc- pi r leans be-
waan assemblages fro
somfcliora Surope
ibbean -ioean©
la*&« * Peedrlsg I
such
Lao t
.y
tion for tropical /vr.erioa.
and from
'P* 102*103$
,
Setffl* 1940 f ebart).
tenuous
■
1
correlations sra e v trer.-sly
need far
&
ate
leselfixa-
Correlation aitli t'ae eta es
52
set up by H* M. Elelnpell in 195H for the California
sequence is difficult, but a comparison
nian
assemblage
t&Hrlbttted
zi&n
hy
wdiiiwA*
■in silt*
Is saggestlte
Klelspell to the upper
stages, "but supposed
Buriigsltan
©no
mni Bell
hi Keen (19*3, P*
anc Helvetian, co;i---ine en asss
*^ fc«
3s)
li a rosea
tiling that of the up par ttublfeaje, lower Progreee, ant
lower Pauls formations*
Eoen t of
>a i
Bornia
:ound Mounts in
kosnas MarJ?s s n. sp* ; c|,ione
CHiiorson) reae&bles
£*
|§||
lit. Is s: Lies to B* |f*}
>
"' ;,E
■
.. ii§
y
)
ii? .i:Jl.aC§SSM
(C«) iauj^na - a ay
AnacMs -atsonae Keen is com "ara^l®
stsysnsoul Marks, n. sp.
a-iornia) tri
i
,
to
n, sp* j
stoanaohls
A larga nta-l.er of OsnssHsiris*
is present in tooth regions. gagasurcula howei Baaae and
Hsrtlsia is seareely different
n.
sp*
toil, guayasenals karfcs,
* and turritella c coven* Oonrai is an;-10.-ous -Ith
1* Infrasarlna.ta
Srsyhoeskl, of whleh a gu»sp#ei#s Is
found in the Subifeai* formation. In all, 16 genera, ln~
eluding 6 subgenera,
oocur in both the Boniwl Mountain
silt and the Suhihajs formation.
If we consider, on this
basis, that the Hound Mountain silt is equivalent to the
naper part of the Oiblbaja formation and the lower part
of the Prograso a
i at
mls formations, mm can conclude
:son*s interpretation of Lowa-' and
is the
saa®
as that applied to Scuador*
- looons
thus the
53
Subibaja formation is roughly the correlative of the
"ogre so
allzian ta. c. or.r i
aula formations
*
bl| mm s end a v
art to the Itciaisn an!
la
Stobnlan Sta
orrslatlons
this
1
leoi.t legy of sac
ha^e been disci seai in t!
oo:r
'v
re -ions of tr:.
ith oth
tions are sxa-
y ■:■■:■'
i
.."
'-y
a. .-.; .:.:
..
m*
$&
station,
*
*&■
v„<■
i* -,*.,. *■-*
page*
Correlation between the Progreso and Baulo Bealae
brings
out the folio in-
vat: Us*
The Lov.er Iiocene
-ibaja forsmtion has no eftreaolej 1calif equivalent stmt
exposed in the fiaule Basin*
tions are
crr-iv
The iroyroso and Bawls forr--»a
la- leally equivalent,, but have less than
one-third of their r-.olluscan species in eorcaon.
sefnance of bio stratigraphic units is no
hoth basins, altfcou
vm
Btxyy-yr^
...ai in
m species oeey y %h
■
hi© positions,
Tk
a rela**
Tfi& JProf-croso formation is
ere closely allied faunally to \
■
Mle the Daule lariations on the same basis, is c loser
to Oolochias
tionships sr©
anct
eos«l4«r#6
ian foraations*
t
re that the
it
"
sse relaY£.,-reso
Pauls maims wars not contiguous during I'lo^ne time.
interpretation of the
a- ladle
a;„
:",;
a d
Hi
rapfey at the beginning of
Miocene time is shown in
figure 1?;.
"
—
—
s^-^s- fc-_.
O. fa
<Tt mj
©» 3*
on
►1
ii rt
*
*
3 3 a.
<t»
mtt O O
W
JO
C
w 03
<» c+
O 3
M<
M
w fe_
»-»
■= P......
>-
>4
H OS
& « aT— S- Si
O
«
?
rt
com.
rt 3
to U
rt C
to Q»
t»
B
:
t» to
—
rt
<V>
a
o
rt
a
QJ
rt
»
»rt
rt
of
to
t)
r-*
H.
!
.
-r
m. 4»
O
3
+*. O
3 O
CO M«
rt O rt
"D »i O
—
I
M-
rt
O
*?
o
a
—&
N--
»
w
o
s—
±t
o
<T»
Tt
-4-4
», — —
fer-Hr-4
" **-"
I
SS
ft]— £So
3* 3
on
9O
3
—
rr
to
tt*
vr>
To
— - i'I
;
m.
O
§*
*
o
I
I nz
1**-8
U> M.
rt
to <-» 3
a* 3
t
j
v
+
—
<
3
W
O 3
g
—
m
s 4—
I
*—
-H
I- H
O
rt
-—
P
9
rt
a
2-
«
3
-3
a r»
3
*
I
p
to
<
to ;&
to
—
(A
c
«->
t
too-
—
—
4-24 -ME"J*
!
Ii
V
W
3
■Hi r.
i
■
t
?
■Sh
If]
- ss
-
b
CO
"-3
i
LJ ,
-+—
2
Trr-
-1
si
m
I
i 1
-4
eH
J
M
I
53
-*4
-»--
I
1
SI s
1
1
f|
1
H
o
c
b
3
H
TO
CI
3*
3
rt
L
w
rt
X 3
o to
_<*\»
rr
(0
1
—— ——
as
i
3
p
1
>i
—r-^
b
....I.
"I
I
5?
**
F
P +1
p
iß.p.kKh
.
I
o
J
M
3
*4H
to m
t)
gf
■
E
„_
X-
—
:
—
to s
* tr
pi
o
3-
rt
4 a! h
M- (p Q.
25
L
it-
£ 3
to
g rt
5 * rt
rt-
43. rt
<<W
»O
rt
♥_*
0
3
.<-»
w
»«-■
A to
3
rt
H»
33
ft s©
rt
P
a> c
aj
■3 to,
0)
ct ;
t*J
3
a
3"
1
-
M
Hi
o3 W
(A
> >
.
SCS rt^ S i
rt
O
M
-X
—
C *H
MO
M-«
PH-— I— r I
B>
M fl>
a *n
t-« C OT
<
>S
s o
x
M
H
ȣ
P.
5^
a.
U
mi
>
9
g
o
W
<»Q,
Is
HE
>
E
-LI
i
<3
H
3
(*---tH*
Xhh-
Ho
3* *1
>
B -5 "-»
M- 3* .**]
e> o
a. ►*
r-» 8 S
ii
i
r*
IVJ
n
t
E^
r—
o
M*
o
5
If
o o
o e»-
-"
-3Q a
»0
3
PL-L
;
444+
*
■
4-.
54
Geologic History
the
Progreso and
ttie PBciilc Ocean
&aale Basins- were @mbaya#st» of
ftvrftaft ■»*! ar:u middle Miocene
Ba&in was an
lProgreso
active during nest
Oiirpeene
air
tiioe.
gr&teun that contin-
tee Miocene epoch.
It subsided
aeewial^
t a ralaUrel* w>ra rapid rata, anc eedlaaata
mm
rabidly within it, fhe Denle tenin praaaaftbly exists
a mMmr&% §«®*pielilia
Use
in a restricted area Hiring Early
and reached its
rcaxiaaa size durlßg &**2.a
Keither doumwari aeveaeat nor deposition
as co rapid as in the k-rotjreeo Basin* At the ©ad of
Middle Miocene tU» a amrine deposition c©aa#d in tooth
| ce> a time*
arc
continental deposits aeenmulsted along the
margin of the ©anle Basin* The @c p« Me rela
a
eastern
lionnfeips of the two basins at the W Imaina: of Middle
I Bene tine ara shown in figure IS*
beginning of the H#ntm#
The Progreso Basin at the
,
*******
Ocean.
epoch, existed as a <t##p umbafMunt of the
low, for the lowsrriru l«*.cs y-i-arantly sere
se#t
. hca
»
f
-a
©shsjs^nt
i
are
©nts ,&***»
eeaJ .**,*«.
■-*' +\%
¥H&
ma-
*-h^
to toe
opened *.**
..*,»
-"<:"
-flttji
xibv,
a
eouira*
or, the
tlie position shown
maifine elastics
v*««*.
jT'O"'.-'1
*■ **la--~i laiE
scales*
■■
paleogao«raphie
that
ac
-.-reae were in
ussp*
figure IS.
wm%, the HolonElena i^ninsnla existed to tim
a loa aaaetf of Oretaeeonii
cha Peninsula to the north, and
The Santa
55
and older rooks to the east,
The Coloncbe Pemimeula ms
a barrier that prevented the direct latere m ge of faunae
between the
.
le
i
:ns,
"
Thm
orthward e:x~
tent of tMfi peninsula is a matter of conjecture
a
tidence exists for en ---sing that it extended much beyond
the latitude of Hants, or vm
onneetad to a larger land
area in the Pacific
ci@s
Miocene Pro
mmn% and
■
rei
Ocean*
sii ...a^ld 1 we had to leave the e&bay*
1 a ta northwestward t
seacard sides of i.
that lived in the
■
i-
far-a i-inrth of the
~ne »r - Oolonche
in order to enter the Dsule eabaptsat.
- I ;--.ulaa
Tbe distance of
bout 500 kilometers ana the i -l»ed differences in en
viroomenta probably ::.indered .migration enough to account
for the
cw rion
relatively small percentage
(38$) of speclea
to the Iro^reeo and Denle Basins.
The Progrea
hayseat probably changed little from this coafi-ura*
tioa until the arid of the Middle Miocene.
b*>ain constituted a
iiamene© ma-r
■""
grafeen, bounded
Hie subsiding
on the west by an
L fault and on the northeast by a eorylox
fault system i arsllcl to tne base of the present Col-;? che
ils,
lerta of the contributing land mass rose as the
r^ben autosided.
Hue surrounding land areas,
;:■: \
.
or parte of the®., .may
deeply eroded during ?iarlv an< l.iiail©
t'L-aCj for the basin sank rapidly,
Kiocene
as shown by the great
56
tbideness of the
tie
v,
eedijsents s
til tec in shallo
-
.
f
. - t.i
ay uthem
i.ro£ ?ra«o
ji
c-?
,
%'H
- c.
locene a^^acls wit,
of an upward tllt'uv
s ot^u sa
Basin c
%s a ion?
i
loc 1 »®rpii
a,
II%iis~
the Daule eubspient at the beginning
gin
Uaule
a of the
the oldest exposed
B|.
O,
.
.
i
: iCBB
Fbey orop out close fe the line :aiowa in figure 12
time, for the correswor,aiag
member of the Biraie
«6.tera a latent
s.;v
a,
«.i
a
"
ailtsta no
formation! were deposited in qutat
Pne waters of t: a
from etiore*
aid not breacn tfaa Miocene
Middle Miocene time,
f&a
"
has been at
or mbofe
inIt c
a
onebe Peninsula*
ndy "ua^er
left as a regreaalve 4a
area
redche ci
a " .-n ta { *Blua
basin apparently was filled to sea level
:
*
faults.
-„. -ant* Tfca waters r
aa the asgo of the
iof
their ; :- O-Jtum extent dur? n tha
sent
wai*
waited farther s.^t < at
Kioceiie apoeb la cot known*
5 ocene
c :-ne roe'
ci --ratien f stopped*
is»
Pocl~. iou.l-3
the extent ©f
of
.
logical studies are
extremity of %vi basinf or in the aijaeent
veatern margin
of tn©
„.
v.
la ,<*ere t
J emboli Orsben.
the
-
'
ti
itic enc time # t
Middle
trace
!"
cess roca
.
r
,f
sediments were
a
tar.
seeded to aaaa %Lc
t t-
yet the
by tfta end of
calcareous" r --a
by tbe retreating
eea»
leirel einee Middle llio-
cene time, since the oolf younger deposits ere of
57
continental type* end they are found
loaeet to the
.ii.uaai
mostly in the part
TUrn central part of
ordlllaara*
the basin Has remained nearly horizontal, whereas the
western Margin has been tilted up ana faulted, probably
to accomodate the uplift of the Colonche
ii^:.q4.
Tita Bolivar gao syncline
Olsson |195£
f
a extent Lag
,ci
i
p,' S3)
fro,::
f
Hills*
end defined by
who showed the geosyscllsal area.
nortiiern Colombia soutbvard through
or to the Paruvien border.
Se indicated that Mio-
cene sediments of the geosyncline may have existed in
a
eo&tiaaaua belt thresh the
pttst Guayaquil*
i.;aule
Basin ana southward
fhe present atwSy shows that the Ilia
cms deposits of the Banle Basin did not extend south
ward to the latitude of Gnaysfnil*
If Miocene litre ta
Gulf
Qoayaipil, they
-or eon
exist in
are
the
n
i likely to
J^-.fceli
be el
epoeits on the margin of
grahen.
Mygren (1980, fp« if#B-S0O5) noted mm* i^;-or**
tant modifications in the structure of the Bolivar geo«
showed that its axis in isarly Tertiary
Hie atatatiise was farther west than in Mloce
sync line*
H®
meat that "the present axis extends fro® northern Perm,
"
paaaea through the Battle Valley,.*. la not documented
by evidence.
It ifi contradicted hy hie maps, «hieh ahow
axis** (presumably the axle from Middle aiocene to Recent time} extending _out!r,ard only to a point
the
58
fha relationship of the Miocene de
north of Guayaquil.
poalta of tpc
«.
*ra
the geoaymcline is
raso Basi
not
I
.-rifled
flic Bolivar geoaynclina of Middle Miocene tise
extended soutfanard to the southern limit o
i#aule Basis*
Bis frogreao Basis existed as a separate
unit and cannot he
the Miocene a-
iocene
co^
"
,
I Mats of the
"
rt of the geosyne line*
3fiO
Basin eaav.ln a
aolluscan assemblage closely related to that of northwestern Peru, but there Is no direct evKor.cc
tUcatea that t:
:
-
..ci
a*-
-ravlart
%
lei in-
locar.o d#
osita were iaid iow In the same structural depression*
59
Conclusions
©
Miocene sediments of the Progreso Basin were
in a narrow, shallowing, sarins emhaytaent during
laid d
T* 0a: . 5.%:
Miocene time.
y and
*
aeane marine
bed in a
seiiiaents of tna Basle Basin were d
-
sn^llow embayment during Mid Is
broad.
time onl
basiaa# as mh«>m by a eoapariaoa of their mollsscan
not coctisuoaa. TH* Program eribaysefltt
assemblage*.,
two
ensd southward to the
,-acific Oceas,
and its aollaaoaa
species show close relationshi m *ith the Peia v
fauna*
sync line,
ta solluscan as
grahen
;o the raoii la )^eaa,
Ned r. arti '
it
to the north,
a part of the Bolivar gee-
ye
fhe Daule embay
is s
¥: c ■aa rose
H.jt
to th
..
s a
■..■
.■
as
formations
f ly als3s La
imrls§ I loeeme Una; the Baule Basin existed as a
shallow geoaysciime*
Both basins were filled to sea level
about the mid of Middle Kloeeai time
sided since*
*,
si
60
DESCRIPTION OP SPECIES
Class FELBCYPODA
Order PRIOHODBSMACB4
Family Mueulanidae
Genus Nuculana Link, 1807
Type {by monotypy), Area rostrata omelln, Recent,
northern shores of Europe.
Subgenus Saccella Woodrlng, 1925
Type (by original designation), Area fragllls Chem-
nits (=» Leda commutata Fhilippl), Miocene to Recent,
Mediterranean Sea,
Saccella has a single posterior rostrum with a shal-
low groove before the carina and a similar shallow groove
anteriorly.
Nuculana (Saccella ) salbana Marks, sp.
Nov.
(Plate 1. figs* 4, 5)
Description of the holotype (a left valvs b
shell
small, not polished, elongate, with regularly spaced con
centric ribs.
Height
length, beak at
AZ%
52$ of length, convexity 16% of
of length from anterior extremity.
Concentric ribs nearly semi-circular in cross-section,
slightly concave on dorsal side, and with nearly flat
interspaces of width equal to that of the ribs, numbering
5/mm.
on center of disk, crowded on anterior dorsum,
thickened at carina, converging beneath beak on rostrum,
61
wit& two of every three
appearing on the
about
1/10
dying out
rostrum,
on the carina and not
nostrum sharply sculptured,
as wide at its greatest width as shell is long.
Carina bald and thickened for about 3 mm* below the beak.
Lunule elongate, narrow, extending about
of distance
from beak to anterior margin, defined by distinct depres-
sion. Umbo barely inflated before center. Beak of moderate else, barely opia thogyrate,
height 6.4
ma., convexity I*9
dimensions: length 12.2 mm. i
bus.
Motes or figured paratype (a left valve): hinge
with anterior row of teeth nearly straight, posterior
row slightly Concave doraallyj 17 teeth in anterior row,
15 In posteriori the anterior row 1,1 times as long
as
the posterior; chomdrophore small, recessed, triangular.
Six valves of this species are on hand.
est and best preserved is the holotype*
type is broken, but would
The larg-
The figured para-
measure about 11 mm. If complete.
Other specimens are smaller and fragmentary.
Five have
the rostrum preserved and show the bald area on the carina.
The stratlgrapalc range of B. salbana is from the
Upper Ollgocene strata underlying the Subibaja formation
to #70 feet above the base of the Subibaja formation in
the
corehole, depth 890-900 feet. Its chrono-
logic range in the Zaeachun sector was thus Late ollgocene to earliest Miocene.
It is the only laolluscaa
62
species known to occur in the Oligocene strata of this
sector.
Materials
holotype no. 80393, Peleontological Be-
seareh Institution, from Doe Bocas corehole Ho. 1, depth
860-070 feet, Xacachun sector, western icuador. faretype
no. £0394 from the same locality. .Pars type no. 7968, Stanford
yniv.
Paleo. type coll., from the sacachun corehole,
depth 890-900 feet;
one specimen from depth 770-780 feet.
Ivuculana ( saccella ) subihajana larks, sp. Nov.
(rlate 1, figs. 1-3)
Baseription (based on holotype and about 20 para-
types); shell large, maximum length about EE mbu, polished, elongate, centrally inflated; height
convexity (of paired valves)
40fl
52^ of length;
of length; beak at
4&%
of length from anterior. Concentric ribs nearly semi-
circular' in cross-section, slightly concave on dorsal
side, usually slightly flattened where nora, wider than
the nearly flat interspaces except on the anterior central portion, extending over the disk to the carina where
they
are lost or barely traceable on the bald, thickened
area, about one-fourth of them reappearing, thin and
sharply sculptured on the rostrum; numbering about
4/mm.
on the center of the disk and varying in different specimens from 3.5 to 4.5, and to as many as
rior ventral portion.
5/am. on
the ante-
Rostrum sharply sculptured, about
63
7,6^ as wide at its greatest width as the shell is long.
Lunula extending about
4/5
of distance to anterior margin.
TJmbones strongly inflated before central line of disk.
Beaks oplsthogyral.
Hinge with anterior row of teeth
nearly straight; posterior ro» slightly concave dorsally;
£6
teeth in anterior row, of which the largest are ex-
tremely long and sharp, the 5 next to the beak very email;
19 teeth in posterior row;
the anterior row 1.1 times as
long as the posterior; chondrophore moderately small, re-
cessed, triangular.
tinguished.
Pallialsinus too faint to be dis-
I4usele scars cordate, located adjacent to
extremities of hinge line. Dimensions of holotype : length
16.3 mm., height 8.8 mm. , convexity 7.6 mm,
Huculana subibajana differs from jj. salbana In its
greater size, inflation, polish,
narrower rostrum, features
of the carina, more strongly oplsthogyral beaks, and greater
number of teeth.
It is more similar to M. (Saccella) calll-
aene (Dall), Recent, which was first collected from mud at
£5$
fathoms,
47.4°
F., in the Gulf of Panama.
Two typical
specimens compare thus?
I*
Length of shell
Height/length
Convexity/length
dist./ length
fidth rostrum/length
Beak
Bibs/mm.
snbibajana
10.3
s&f§
23f§
45$
iism,
7.6$
4.0 (ay.)
Jl. calllmene
14.8 snu
5Ef6
214
49£
5,4^
4.0
64
(continued)
j§# sublbajana
Lunula
Hot depressed, Depressed,
sculpture con- sculpture distinuous
cont inuoue
Anterior teeth
Posterior teeth
'
Length post./ant. teeth
Surface
Jf* callimene
26
27
19
18
91%
pollM
|M
p>llthrt
Of the differences shown above, those of convexity,
the lunula, and the rows of hinge teeth are the most evident.
Hueulaaa (aaooella) peruviana (Ball) from the Upper
Miocene of 'Pbtu is similar to N. aublbajana, but, according to the figures in spieker (lt2B)f is less attenuated
posteriorly and according to Spieker* s description le
coarser sculptured, has fewer teeth, and lacks a welldefined lunula.
S. sublbajana differs from N. commutata (Phil.),
the type of saccella, mainly by lacking the anterior constriction and the slight angulation before the carina, and
by the tendency for
some ribs to die out on the carina.
the stratigraphle range of jr. sublbajana Is from
816 feet to 1790 feet above the, base of the Subibaja formation, Lower Miocene.
An overlap of 2.75 feet
exists in
the lower range of N. sublbajana and the upper range of
!"
eelbans (q.v.). J§. sublbajana apparently thrived in
a habitat of fine sand and silt. Associated with it are
.
Pitar aff P. thompsonl, stromblna peqyenita, Anacbls
stevensoni, Chlone proplnq.ua, etc.
65
Material: holotype no, £0396, Paleonto logical Hesearch Institution, from the Sacachun corehole
150-100 feet.
Paratype
,
depth
Paratype no. 20397 from depth 80-90 feet.
no. 7969, Stanford
depth 500-510 feet.
tjnlv.
Paleo. type coll.,
Additional material from depths
60-71, 80-90, 100-110, 140-150, 450-459, 550-500, 1000-1.011, and 1041-1050- feet, and from Bos Bocas corehole
no. 1, 70-80 fiat* and from locality 1437 in the Daule
formation.
Subgenus
Adrana H. and A. Adams 1858
f
Type (by subsequent designation, atolic^ka, 1871),
Huoulana lanceolate (Laa. )
* guoula
lane eolata Lamarck,
ISI9, not Sowerby,' 1817 (* Hucula taylorl
.., . Hanley,* 18©0).*
.. .....■■»
"
W
Pi»l«lliH»Pl|l»HPIl.l»liH
|f|
V
;|
taylorl lives off the wast coast of
*
Nuculana (Adrana)
vm.m
,*z*m<.<mtm i
i
l
im^.mm*».**mofm
w
>tn
nmm»:Mmmmmmmmmm»
Central America, fide Beeve*
fhe subgenus
.
n
#
.was evi-
dently fully developed in Soees&e times*' { Harries Bull*
mer. False, vol.
0, p. 71).
Huculana (Adrana) sp.
(Plate 1, fig. 6}
Description (based on two specimens}? shell elongate, moderately
convex, with the beak at 11/29 of the
length from the anterior extremity,
sculpture of fine
,
concentric lajaellae, oblia.ua and bifurcating at the
slight angulation that separates the posterior one-third.
66
Ventral navgia essayed Just behind middle, Dlssenslone
of figured epeetsien, length (estimated complete J29 mn* f
Might B*7 ms** convexity (one valve) 3*o uss*
second, speetaen {eetlsaetM complete)
35
length of
im*
A ttolfd apeeteen (locality X#P«C* B&BBi Is similar
and sosnevbat distorted, laughs 19*0 m** height 6*o me*
A search of the llteyetma reveals no exactly com*
pamhle form.
hypo type no* 80390 t
Materials
i^ieonteloslee!
«ee*eh Institution* itmt Bo® Bocae corehole Sen
1*
fte~
depth
feet* etreiigipepMeally 1386-1396 feet above the
base of the Subthaja foramtioa. Lower Miocene* A seeoni
specimen ftme tba same locality* One specimen frees locality X#P*o* E650» las Baaas sector* Sublbaja formation*
7O«*§o
Lower Mioeetse*
JNOmMLj Olyeynerldtai
Subfamily 01ycyatrliiae
Senue Olye^merlc BaCosta* 1778
(by
Type
ff«r
»«F
4rea
,
tamtamer^*
w
w
*■ p
h»,hi«;i.i >ii»i.p
Linns, Recent*
ulycymerlf*
«<i»iiirffii. Uiiii«»p»pa.'ii-i.»p,i,.»-»^.
)
P
W
northern Europe*
Subgenms glyc^yrlf a*a*
a.lvagwagla
IQlycwaarls, j
sp*
A pair of speciiiena was found at locality I*?*o*
1134* Baule formation* If166la IHaiiaa< The
epaalaa fesam-
** (1911,
bles **
0. oarabaatna Brown and HlUff
p*
awH»i.PP[>i. «pm»»pWl».l
IPi'-'PlP"H.»'P»<l»'
363*
PPr^-*
pi* S6"9
par-."
67
fig. 9), but has about six fewer ribe and is somewhat
less Inflated than G. carahaalna*
the primary ribs
carry low, faint secondaries.
Family Boatiidae
Subfamily Boetil
nac
Genus Noetia Gray, 1857
(by
original designation).m Moot
*
*
la triangularis
fjv*
mm nm
imm*\>mmm<imm*mmwti tirwwmriiiiTrrini
"
t*
v
*.*#
-*#?
v
-~i -jltiv iiinn
mj
minima
reyarea Sowerby), Becent, west ooast of tropi-
Area
cal America.
Boatla flaulaana Marks > sp. now.
(Plate 1, figs. 7-9)
Description (based on holotype and 3 paratypea):
Height about
3/0
of length i ahall suhrhamboidal; convex-
ity of one valve about
low
j
4/10
of length*
B**aki§
moderately
situated above a point 44$ of the distance from the
posterior
ana
to the anterior end of the denticulated
part of the hinge plate.
U<abonea hi#j umboaal ridge
carlnate and curved toward the postarovsntral extremity.
Bibs 34 t with 10 on the posterior slope and 14 on the
main part of %hm diak, about ec.ua1 in else to the Interspaces*
rounded on the posterior slope and the early main
part of the disk, flattened on the vantral portion of the
main disk, ornamented with fine, scaly concentric lines
that cross the ribs on the early part of the disk, but
68
are visible only in the interspaces of the ventral part*
Interstitial ribs tall developed on the posterior slope
and the first three interspaces of the posterior portion
of the main part of the disk.
extending about
1/10
Ligament mostly anterior,
of its length posteriorly.
Hinge
line composed of two nearly straight segments forming an
ohtusa angle of 145
degrees;
L-shaped anterior teeth num-
ber 10, strong posterior teeth IS; posterior row of teeth
9/10
as long as anterior row.
Dimensions of holotype i
length 33 mm. t height £&§ .mm., convexity (right valve only)
13 mm.
ixaaination of six specimens from the Dsuie area
shows that the height-length ratio varies from 78$ in the
holotype to
B&i In the tallest specimen*
The largeet
specimen available, 43 mm. long, has a higher llganental
aroa and
stronger shell,
the normal features*
but no other great variation from
There Is little variation within the
species.
£"
dauleana does not 'appear to b# closely related
to any of the described species.
£" ecuadorla MacNeil
It differs sharply from
in position of the beak, shape of the
muscle scars and hinge plate, and breadth of the umbonee.
The shape of the hinge is more like that of
Jf. mauryae
MacHeil, but H. mauryae has beaks situated more posteriorly,
a shorter posterior row of teeth, and a generally more
69
elongate shape.
N. colombiana Kaefieil is more inclined
to the posterior, with a much shorter posterior row of
teeth,-
is. macdonaldi Ball has a more
"*
m& a shorter posterior
row of teeth.
(Banna m& IsraeXsky) has lower feeaka,
curved. hinge line
N. retractata
mmm
a
..p.!...pp nMiiii ■ i i
i i «»lp«p»
shorter pos-
terior row of teeth, and a more curved anterior hinge
plate.
A small specimen from. 100 feet above the base of
the Gatun formation, about five miles east of Colon,
Panama, has
all the features of 8. dauleana, and may be
an immature specimen of this species*
J§* macnalli Marks
(q.v.) from, the Lower Miocene of the Progreso Basin may
he the ancestral species of I. dauleana.
£* dauleana only in number
It differs from
of ribs and shape of hinge*
The new species Is known to occur only in the
*81ue slltatone" member of the Baule formation, Middle
Miocene of the Paula Basin, southwestern Ecuador.
Materials holotype no. £0399, Paleontological Research Institution, locality I.P.C. 1456; par&type no.
£0400 (figured), loc. 1450;
m*
SO4Ol {Z specimen*), loc.
1458; no. EO4OS, loc. 14§1; no. 50403, loc. 1134.
Pars-
types no. 7970 (two specimens) Stanford Univ. Pale©,
coll. from locality I.P.C. 3439, east of village of
s
Caleeta, Manabl Province.
type
70
Hoatia macneill Marks, sp. Nov.
(Plate I, figs. 12, 13)
Description (based on holotype and one paratype):
shell medium-sized, subrhomholdal; height about 80$ of
length; convexity about 37$ of length; beaks situated
above a point half-way between the extremities of the
denticulated hinge plate; posterior margin straight;
anterior margin gently rounded; umbones high, rising
about
13$ of total height of shell above level of car-
dinal area,
sculpture of well-defined radial ribs and
occasional concentric thickenings; radial ribs 11 on
posterior slope* 30
on remainder of disk; fine (primary)
interstitial radials sole sculpture on first one and onehalf millimeters of beak, extending about half-way over
umbo on most of disk, continuing to margin on posterior
slope and four adjacent interspaces, except in three pos-
teriormost Interspaces where obsolescent near margin;
concentric ornamentation of fine, scaly lines on ribs
and interspaces with radial ribs prominently adorned only
on dorsal half of disk. Posterior slope flat and separated
from rest of shell by interfacial angle of about 97 degrees
on adult portion of disk*
Area with a bar®
strip behind
beaks, and higher posteriorly than anteriorly; ligament
mostly anterior, extending from
length posteriorly.
1/10
to
1/0
of Its total
Hinge plate composed of a nearly
71
straight anterior segment with 10 L-shaped teeth an-
teriorly and 5 crowded straight teeth centrally, and a
long, gently curved posterior segment with 4 straight,
crowded contra! teeth and 14 L-shaped posterior teeth;
anterior
segment
7/8
as long as posterior segment.
In-
terior crenulate on margins; palllal line entire except
for a slight, dorsally-dlrected curve over thickened sec-
tion of shell near central margin; muscle scars unornamented, the posterior scar separated by a sharp, thin
ridge and the anterior scar by a low, thin ridge.
Ho
significant variations noted in two type specimens, ex-
cept that the ligament extends slightly more posteriorly
in the holotype. Dimensions of holotype, a right valves
length (incomplete), &3.,8m ,; estimated total length,
26 mm.*, height 20.7 mm. ; convexity. 9.4 am.} hinge plate,
14.5
mm*
Dimensions of paratype, a right valve: length,
25 mm.; height, 18 mm. ; convexity, 9.3 mm*; hinge plate,
14.3 mm*
The nearest relative of N. maenejli should be N.
stewartl MacMell from the uppermost oilgoceae of
£* fftewart;t
has about the same number of
Imvu,
radial ribs, the
same strongly developed Interstitial ribs, mostly anterior
ligament, posteriorly wider cardinal
area, and centrally
straight teeth; but it also has a curved anterior hinge
plate, whereas K. magnalll has a neerly straight anterior
72
hinge plate, and it has much higher umbones and a greater
height/length ratio (90(^) than N. ma oneill (80<€).
Fig-
ured specimens of N. stewartl are about 10 mm. longer than
the types
of
'
X
I* macneili.
*PHP
...«.|PP..,, 11l
|P
.IMP.IMIP
*
The known species
nearest to
Mm macnelll is K. dauleana Marks .from the Middle Miocene
of the Daule Basin, Ecuador.
N. dauleana has approxi-
mately the same shape, proportions, cardinal area, muscle
scars, and indented psllial Una as |f. macnelll; however,
£" dauleana
has a slightly more arched hinge line, seven
less radial ribs, slightly more posterior beaks, and interstitial (primary) ribs subsidiary to the (secondary)
strong
radials on the beak, whereas in g. macnelll the
interstitial ribs are the sole sculpture of the beak.
The holotype of Koetla macnelll occurs 1408 feet
above the base of the Subibeja formation.
The paratype
occurs 405 feet stratlgraphlcally higher in the same sec-
tion, 13 feet above the base of the Progreso formation.
The fauna associated with g. ma one ill includes
Huculana sublbajana, Chione proplngua, Pi tar (Lamelll-concha) zacachunensls, Tellina sp. , Bornia. (Temblernia)
kesnae, Potamides infraliratus, and the crab Callia-
nassa (?) sp.
These species, together with the silty to
sandy lithology of the enclosing rocks, indicate a shallow
neritic-zone habitat in an area of rapid sedimentation and
probably somewhat turbid, barely brackish water. Jj.
73
»acnail| Is named fm w. steams MssKall is recognition
of his work on tha Tertiary Koatlaaa*
Typ& material! holotype no* E0404 and p&ratyps
no. £0403, falacratologloal ftaseisreh institution. Holotype from jsaathaa corebole, depth 4§o-45t feet*
ffcffta
%fM trom depth S^-48 feet.
IM #$*
(Plate i, figs. 3, §}
4 single apseliasfi of a large, strong-ribbed Mootla
saa found
at locality UF*s» 11301 in the sublbsja f®mm~
tiaa of the Las Kasaa sector*
Th# description of the shell,
a left valve, las shall large,
at. ia
crats, with moderately
high umbo,
asdlni sculpture of 5S *Hms, Mon tha m%M
part of tha
diak^ 10 flattened ones on the
Cardinal area mo<*-*rataly low, with 1.
'-a
irlor slots*
sat
axt#;
posteriorly and It as* anteriorly from canter.
v-y la nn.
Hlafa with
five t*ahaped teeth in m row of tasltra strong posterior
teeth, about 40 smaller central teeth, two strong L«ahapa6
anterior teeth, and a small anterior nub of a tooth. Binge*
line gently curved, with main curvature toward the posterior extraoity of hinge-plate.
PlSMiaalaaat length §8
Height ®§$
of length.
anu ,height ft! ma* , convexity Iimm*
fbls apaalaaa is appataatly aat closely related to
any other described itoetla*
It occurs In the Lower Miocene
74
strata of the
Frograso
Basin.
Materiali hypotype no* S€4o§, Paleontologies! ftesaareb Institution, from locality i.&.Gm 11201.
family ireIdas
c*® Iim® &g*,dara Gray, 1647
Type (by original designation) Arse sntl quata
Lisa*'*
accent, tropical and subtropical* Im#® -Pacifit*1
mmmmm-m^mimmmmw'm&m*!
mm., mmmmm pmm
...
mm . wmmm* mm tmmmmmm mmm m
■
*%»» identification of A. antlauata as an example of the
present Indo-Bioifio apeclaa ©y ''IS* €i»ing and other
conchoiogists in the past is falls correct** (I**l* oox,
Beport on tha Pal«ont©le«f of Zanzibar Protectorate, p*
ti, 19£7)»
flelnhart, 19%, and Belnhsrt and sebanek*
1926, have stated that the habitat of ft* , amtlquata is
##et Indies,*» Specimens labelTW^Hara
<t
aat.i<Lgata. la* the Stanford collection are frFmTKT
fHo-tacffie
subgenus jnadara , s«s*
"Shell efniwalva, eontiomly Inflated, heavy,
eloagata-oval la outline; unbones materior to
center of aba11} beaks prosofyroua, pointing
inward; length of adult shells usually to to
73 millimeters, rarely 1.30 mm.} external sculpture of regular, strong radial ribs, which ar®
plain, beaded, or grooved; interspaces often"
squarely excavated; concentric sculpture
usually stronger on interspaces than on ribs,
sculpture of two valve® stalls** both as to
number of ribs and €®&?m and kind of ornamentation, moat species pm&mm from about 20 to
40 radial ribs; when attached, two valves close
tightly, lacking a byssal gape; ligament external, occupying practically all of the troughshaped ligaments! area between beaks and extending the length of dorsal margin, both
75
anterior and posterior to beaks % surface of
ligaments larea usually grooved by chevronshaped or, more rarely, by straight, longitudinal lines.* .shall porcellaneous., " Distributions cosmopolitan, in lira, shallow
water; marine. Time *
* fongrian (early
raises
Oligocene \ to Recent.
1 Scbsnck,
arcid peleH.0., and Belnhart,, P*W«, Oligocene Hist,
cypods of the genus Anadara Mem* Mus. roy.
net*
Belg. ser. 2* fase.~l4, pp* 14-15, 1938. The range of
Aisadara must be extended to include the Late Eocene, since
two species of A. ( Anadsrs i occur in the Upper Eocene of
Colombia (of. oTark' and'" 3&rhaai, Seal. Soc, America
Ilea?, 16, 1946, p* 31U
,
"
«».».Pl#*W.»..WPPW«»«*.».,4iiV**«lM)Mi^^
Ana.dara (Anadsrs / a1ergsda Marks,
sp*
nov.
(Piste X, figs. 10, 11}
Description (based on holotype, a right valve, and
nine paratypes);
shall moderately smell, elongate, equi*
valva, Inequilateral, with no byssal gape, height about
$1% of length on
young adult.
Margins
Internally crenu-
late; dorsal portion of anterior margin sharply rounded,
ventral
portion straight; posterior sasrgln truncate, Uis-
bones low wi.th "barely pereeptibls mesial Impression near
beaks.
Beaks small, s!»rp, prosegyml*.-*, bsre, situated
above a point
if4
of distance from anterior to posterior
extremity of denticulated hinge plate*
ladial sculpture
of 23 simple ribs, sub-rounded in cross -section and larger
than Interspaces on posterior and anterior extremities?
square in cross -section and smaller than the slightly concave Interspaces on center of valve, irregularly grooved
by concentric growth lines nn& fine stria©
tion of older shells.
on ventral por-
Posterior slope with six ribs, set
76
off from rest of shell by angulation with interfacial
angle of about 30 degrees (internal angle),
cardinal
area low, elongate, inclined at low angle, with about
four chevron- shaped ligaaental grooves on young adults,
eight on gerontic specimen; earliest three grooves crowded downward below beak.
Hinge of each valve nearly
straight, elongate, slightly thicker anteriorly, with
about £5 anterior and 3B posterior teeth,
Teeth slightly
convergent at extremities of hinge plate, divergent or
vertical centrally.
Interior marginally crenulate, with
fine, faint radial striations, nearly square posterior
muscle scar, and anterior muscle sear well forward in
anterior projection of shell.
height
3*7 mm. has a
An Immature specimen of
strong mesial sulcus
on the umbo,
a straight, truncated posterior, and fine, regular concen-
tric striations on the umbo.
Older shells are more
strongly convex, with higher cardinal area and thicker
shell material. Dimensions of holotype, a right valves
length 18*7
mm., height 11.3
mm*,
diameter 3.6 a**
Dimen-
sions of largest specimen, an incomplete left valves length
(estimated) 53. 3 m*
, height
14.3 mm., diameter 3.6 mm.
The features that best distinguish A. alargada from
other species are the simple, square outlined ribs and the
straight antero-ventral margin with correspondingly small
anterior extremity.
77
Anadara alargads does not appear to be closely re
lated to any of the known Anadaras.
In general outline
and hinge characters it resembles the Miocene species a*
" from Panama,* A. honensis
*
darlensls (Brown
and Pilsbry)
mm
...^.
,...,.-
ii ii, i
>i,mM
(Olsson) from Costa Rica, and A. cornelians (H.K. Hodson)
from Venezuela.
However, A.
dariensis is a seapharea
with lnequal valves, split ribs, and nodes; A. honensis
has a more rounded anterior and a curved posterior ridge;
and A. cornellana has more ribs of rounded cross-section,
fewer teeth, a more rounded anterior, and, like A. darlensls, is probably a gospharsa*
The holotype and a paratype occur 1317 to 1337 feet
above the base of the Lower Miocene subibaja formation.
The remaining eight types occur about 1393 and 1133 feet
above the base of the subibaja formation,
©lis makes a
total stratigraphic range of 300 feet for the known speci-
mens of Aaadara alargada.
Associated with Anadara alargada are Kuoulana
. — .. . .
.
(aas-
' » and Turris
*
* sublbajana, a large Muculana (Adrana),
oella)
..
i.i
ii»—
i««
p» .mi■
p..
,X... :,.oi: ii»«p»
(Polystlra) sp.
"
Ilin
uiiiUpp
i.ipii
I
iPp
Hum
I aiiln
'i.np.
,..»
.lipn
I
Ullliu.
The specimens occur in a fine, issssive
siltstone with calcareous marine foramlnifers and occasional fish scales.
The trivial name alargada* Is from
the apanish and means 'elongate.'
Type
materials holotype no. 30407 and paratype no.
30408, Paleontoioglcal Research Institution, from the
78
Zacachdn corehole, depth 550-560 feet.
Paratypes no. 7911,
Stanford Uni v. Paleo, type coll., from 710-720 feet. Para-
types
no* 20409,
Paleontological Research Institution,
from Dos Bocas corehole no. 1, 70-80 feet.
Subgenus Cunearca Dall, 1898
Type (by original designation), Area incongrua Say,
Recent, southeastern United States.
Cunearca differs from Ana&ara, s.s. in being inequivalved, disc repantly sculptured, usually thin-shelied,
high in outline, with prominent beaks.
The left valve
bears prominent nodes which are not conspicuously developed on the right.
Scapharca Is intermediate between
Anadara and Civnearca.
mmm
1 Reinhart, 1935, p. 46.
wt*■>.«!»
mmm<"»««.«_ mmmmmm
mm-mm
PPWOPi
—
Anaflara (Cunearca ) thalla (Olsson)
(Plate 2, figs. 1-4)
Area" ( Cunearca ) tha11a Olsson, 1932, Bull. Aiaer. Paleo,,
68, pp. 69-70, pi. B, figs. 7, 8, 9.
vol. 19,
"n0.
A. tfaalia occurs in the Lower 2orritos (Lower Mio-
cene ) formation In Peru.
In Ecuador it is a commonly oc-
curring species in both the Progreso and Daule formations
of Middle Miocene age.
The lowermost Ecuadorean strata
that contain A. thalla are the siltstones of the upper-
most Subibaja formation of the Zacaehdn section, where it
79
is associated with Chione proplnqua and Crug
!turricula
"in rr n.- r
m
■piiiKi
»iimi p
ipnp.p."
pt'i. in.11 in
pYkppii iip.ii. ipvip.,l.
Mirii
i
i
i i nil11 Liv 1
cruziana.
Material;
hypotypes no. 20401, Paleontologies!
Research Institution, from locality I,P.C. 3439, northBaule Basin, Manabi Province, Ecuador; Daule forma-
tion, Middle Miocene, Further specimens from the
2acsebdn corehole, depth 130-130 feet, upper Subibaja
formation, Lower Miocene; depth 43-30 feet, basal Progreso formation, and from localities
I.P,C.
*
1080, 1134,
1436, and 1461, *Blue siltstone1 member of the Baule
fonaation*
Family Ostreidae
Oenus Ostrea
Linn^* 1758
Type (by subsequent designation, Schmidt, 1818),
Ostrea edulla Llnodf, Becent, coasts of Europe.
Subgenus Crassostrea Sacco, 1897
Type (by original designation), Crassostrea Vir-
giniana (Gmelln) « Ostrea
vlrglnlca
Gmelio, Recent, east
coast of Horth America*
Ostrea (Crassostrea)
sp*
A vmvj large Ostrea occurs in the basal strata of
the Progreso formation in the Zaeaehdn sector. It has an
80
elongate ligaaental
area flush with the inner valve surface,
a thin shall, ana concentric laminae without prominent folds
or radial ornamentation on the
outer
surface. Dimensions
(a left valve): length 103 mm., height (nearly complete)
338
The right valve is thinner, more orbicular, convex,
ami.
finely laminated, and smaller than the right.
Material: one left valve and five right valves from
locality I.P.C. 7777 at Zacaehw.
Ostrea (Crassostraa) sp. b
This species also is present in the basal strata
of the Progreso formation, Middle Miocene. It is elongate,
thin-shelled, with an elongate iigamental area raised above
the floor of the valve.
.
The loft valve Is strongly convex.
The concentric sculpture is of rather coarse laminae.
right valve la
The
elongate, rather thick and nearly flat.
Dimensions:' length £8 mm., height (nearly complete) 44 ima*
Materials a left valve from locality 7777 at
ehun.
zaca-
A right valve from the 2acachun core-hole, depth 45-
-50 feet.
Subgenus lopha R3ding, 1798
Type (by subsequent designation, Dall, 1898), Q strsa
cristagalli Llnne, Recent, Indo-Pacific*
SL* foppha) cristagalli has 6 to 8
ridges, is thin-shelled, and has a wide,
V-shaped radial
short hinge that
81
is very subdued on the left valve, barely overhanging on
the right valve.
Q strea ( Lopha )
sp.
(Plate 3, figs. 7, 9)
This ornate Ostrea occurs in large numbers la the
"Upper calcareous* membmr of the Daule formation, Middle
Miocene,
£"
It is larger and more strongly sculptured than
gm>Ml loodrlng of the Bowden Miocene, and has
more
radial plications than 0,
hai
tens!s Sowerby from the Midmm
<*mmm*w«m^**m*mimmm-m
die Miocene of Santo Domingo.
▼
The average specimen is
about 65 x 65 mm.
Material: hypo types nos. £0411 ana 30413, Paleontologies! Research Institution, from locality I.P.C. 1444,
10.8 km. S 70 f of the village of Jerusalem, Baule Basin,
Ecuador.
Family Paetinidae
Oeaus Pocten
Miller, 1776
Type (by subsequent designation, Schmidt, 1818),
Ostrea maxima
Linns', Hacent, lurope.
Subgenus _4^ui;gecten Fischer, 1886
Type [^7 monotypy), Ostrea opercularis Linn©'
..
..
Specimens of ?. (Aequlpectan)" opercular
*"*
is from m&m.«»■
"mm
w.i»<.,.pipipll.»i.iip|..iiiTl'.
p..i..
...p ppi.ip.pp.
"ii
itm
■.ipiiißiiimniiii
-pp
...^prti
land have both valves alishtjy convex, the left valve more
convex than the right. The shell is equivalved except for
82
the ears, the ventral ears being concave (at the byssal
notch in the right valve, before the byssal projection
In the left valve), the dorsal ears straight on their
margins.
The shell is very slightly Inequilateral, be-
ing elongate postero-ventrally.
has s ctenolium,
The byssal ear, which
Is similar to that of P, (Chlamys)
islandions, the type of Chlamys.
The sculpture is of
19 low, broadly rounded ribs with numerous, finely imbricated secondaries that are sore prominent In the Interspaces.
The average shell is about 70 ism. long.
Peeten (Aeoulpecten) plurlnomlnls subsp. prpgresoenala
Marks, subsp,
nov.
(plate B, fig. 8; plate 3, figs. 4, 3)
Description (based on holotype and 16 paratypes),
shell moderately large and convex, the valves nearly equal
very slightly elongate postero-ventrally.
Ribs 17 or 18,
rounded, with very little interspace, ribs and interspaces
striated hy about five or six low, contiguous, rounded,
scaly
or spinose secondary riblets. Byssal ear with scaly
riblets; other ears subequal, finely striated.
crurae one pair, elongate, moderately heavy,
Auricular
ctenolluja
with six to eight teeth. Variations noted In strength of
crurae; strength, size and number of secondary riblets;
and size of shell, which includes a complete series of
83
smallest, height 24 mm. , to largest, height 50 mm.
sions of holotype, a right valve: length 36.4
Dimen-
Ma. ; height
(incomplete) 34.0 mm. ,(estimated complete) 36.5 mm.
The new subspecies differs from P. plurinominis
*—
v
.Klip.
_Bi«w«wMiwtii«wiii'
nittmrnrnt—Mm-miMum*
Filsbry and Johnson from the Santo Domingo Miocene
iimmmmmmmm
only
1 Proc. Acad. Hat. Sci. Philadelphia, vol. 69, 1917, p.
173; vol. 73, 1921, p, 411, pi. 45, fifes. 1, 2.
in having one less and slightly wider ribs, and in attaining a larger size.
identical.
The sculpture pattern is virtually
The new subspecies is also very similar to
£" plurinominis morantensis Woodring
from the Bowden Mio-
cene (1925, p. 67, pi, 8, figs. 4, 5), which also is
smaller but has one more rib.
P. buchlvacoanus H. and K.
Hodson (Oligocene) and its subspecies p. maracalbensis
1
and P. falconensis (Miocene) from Venezuela are similar
mmm>mmmmmmmmmmmmm&mmmmmmmm*mmm mm*mmmmmmmmmmm*mmmmmmm mmmmmmmmmm
1 Bull.
Amer. Paleo., vol. 13,
1937,
-p^.
29-31.
and need comparison with specimens of P. plurinominis and
its subspecies.
In general, the Venezuelan forms seem to
be more heavily sculptured than P. plurinominis.
far from P.
They dif
progreaoensis in details of size, shape, and
secondary sculpture.
Compared with the living West Indian species P.
exasperatus Sowerby, the
new subspecies has broader, lower >
84
and scalier ribs, a. narrower byssal ear, and heavier
auricular crurae.
P. plurinominis progresosnsla occurs in the middle
portion of the Progreso formation, Middle Miocene, of the
Progreso
sector.
Its known stratlgraphio range there is
approximately lib maters, plus an undetermined interval
toward the base of the formation.
It was not found in
the basal strata of the Progreso formation, nor in the
underlying Lower Miocene Subibaja formation.
Associated with p, proyrasoansla In a sandy matrix
ias
Megapltarla olssonl.
The subspecies is named for the town of
Progpreso,
near which It occurs.
Material! holotype no. 30413, Paleontologies! Hesearch Institution, from locality l^*G» 30SS, exact location not certain, but believed to be the same as I,P*C.
7768 (q,v*).
Further paratypic material, 9 specimens from
localities 728 to 737, from 10.0 kilometers H 72® ito 7.9
km*
a 83° lof ihe
town of Progreso, Paratype no. 00414,
P.H.I*, from locality 736 (figured).
from locality 726.
Para type no. 20413
Paratypes no. 7972, Stanford trniv,
Paleo. type coll,, from locality 728.
85
spieker
Pecten ( Aequlpecten) woodringi
mM^itmf>»t3mmm
twm,m*<iAf"mmmimlmm.w>-,
mmmmmSPk\HtmiMtWn*mttmt'\im\t n. iiuium*
-^.'-'m^mm^vmimt«u.i f
(Plate 3, fig. 1)
.
Pecten sp. md. Kelson, 1870, Trans. Connecticut Acad.
Sci , vol, 2, p. £03 (in part) (fide Spieker, 1922
and Olsson, 1932).
,
Pecten woodringi Spieker, 1922, Johns Hopkins Unlv.
studies in Gaol. no. 3, p. 125, pi* 7, figs. 4,5.
,
Pecten (Plagloctenlum) woodringi _picker, Olsson, 1932,
""lull. Amer. Paleo., vol, 19; p. 81, pi. 5, figs. 2,5.
As
(1932,
*
* *p. 82),
* * mum
P. woodringi
noted by
■> Olsson
ili
mWifaiMi
,ip,.pp...i,p.n..,.
i
mill i
closely resembles the living west coast species P. turnbe zensis,
right valve
squarish ribs with wide interspaces on the
are common to both species; but P. woodringi
has a slightly larger ligament pit, a straighter auricu-
lar crura, the ctenolium Is more strongly toothed, and
the byssal ear is more heavily sculptured,
status, living
P,
pauclco-
on the west coast, is very similar to P.
1
tumbezensls, although specifically distinct.
P. glbbus
1 The writer is indebted to Dr. L.
0. Bertlain of the
California Academy of Sciences for msny instructive
comments on the classification of this and other Peetlnidae.
nucleus, living in the iest Indies, has internal charac-
ters similar to those of P. woodringi , but is more In-
flated and has more numerous and rounder ribs. P. effosus
Brown and Filsbry, judging from specimens from the Gatun
formation in the Thompson collection, is similar than p*
woodringi, has narrower ribs, lamellar growth lines that
86
p. woodringi lacks, and more crowded concentric sculpture
on the byssal ear; however, the same elements are present
In both species.
Dimensions of figured specimen, a right valve
length 29.7 mm,
, height
27.6 mm.
stratigraphic occurrence t upper portion of the type
Progreso formation, Middle Miocene.
Material; hypo type
no. 20416, Paleontologies! Be-
seerch Institution, from locality I.P.C. 499, 7.9 kilo-
meters 8
21®
Iof Progreso, Ouayas Province, Ecuador. Fur-
ther material from localities 531 and 532, Progreso sector,
and 7498, gaeaehtin sector.
) aisenensls Marks,» so. Nov.
'
Pecten ( Aequlpecten
.,
linn
iii i
i i i iii.p
iii.u.iii.rili
vi i
irtlin ii .11
.11
iniip
ii
iliiiin
pmiwipi ■'iiiin.pni
i-
(Plate 3, figs. 2, 7)
description (based on holotype and two paratypes):
shell rather small, moderately convex; valves sub-equal,
slightly inequilateral, slightly longer than high.
Sculp-
ture of 20 ribs on each valve; ribs rather high, rounded,
barely larger than the deep interspaces, ornamented, with
about six rounded, scaly secondary riblets which do not
appear except near ventral margin of shell (probably because of erosion); interspaces with one subdued central
riblet; concentric sculpture of closely spaced
lamellae on
ribs,
,
subdued
Byssal ear with moderately deep notch,
wide sear, two closely spaced riblets and three broader
87
riblets, all heavily wrinkled in a sinuous pattern.
Bight
anterior ear and both ears of left valve with eleven fine,
wrinkled riblets. Ligament pit of moderate size.
lar crurae one pair, rather heavy,
elongate.
Auricu-
ctenolium moderately
Dimsnsions of holotype, a left valve: length
30.4 mm, , height 28.9 mm., convexity 7.5 mm.
Dimensions
of paratype, a right valve (figured )j length (nearly com-
plete) 26,6 mm.
, height
26.9 mm., convexity 4.5 mm.
This species is closely related to P. plurinominis »
differing from P.
plurinominis and its subspecies mainly by
being .smaller and having more ribs and weaker secondary
sculpture.
The lack of secondary sculpture on the
earlier
part of the shell is probably due to erosion, either chemi-
cal or mechanical, during the life of the animal.
The only
known occurrence is at locality I.P.C. 508, near Progreso
town, in the upper part of the Progreso formation, Middle
Miocene.
The type material consists of holotype no 20417
(a left valve) and paratype no. 20418 (left and right valves)
in the Paleontological Research Institution.
Order
mB0X)18NlClA
Family Orassatellidae
Genus jgueraasate11a
Type (by original
Iredale, 1924
designation),
Lamarck, Becent, Australia.
erassate lis klnglcola
88
lucres sat ells berry! (§ploker.)
Orasaatellltes (aca-oul*) berryispieker, 1912, Johns
Hopkins Unlv, Studies in Oeol. , no, 3, pi. 7, figs.
9, 10, p. 131*
berry! .fgpieker, Anderson* 1949, Pros.
<^Tl£ssnls^Ac»ao, sol,, ser. 4, vol. 18, a* 139
grou^, horizon If the present writer has
/Tubsra
specimens and concurs in the identifiesthe
seen
*
OU/
Crso
"'r
V- A
.T^voTT
lucraggattlla (Hyhologhue)
berry!
rpaleb
SSr
30T2T7T35X1.
®$ (lower
&,§,s.
,
olsson,
It, pi. 6, figs*
Miocene of ?m®}*
A trio of specimens was found in the Lower Miocene
Subibaja formation of the Las >ia®aa
sector,
several
m4
mora in the Middle Miocene Baule formation. The Peruvian
occurrence is Lower Kiooene and the Colombian occurrence
uppar Middle Miocene »
fetorials three specimens from locality
l*p*c.
11202, Las IJasas sector; several specimens from localities
I,
P.C,
1162 and 1464,
,f
ßlu©
siltstone" member of the
Baule formation, Dsule Basin, Ecuador *
"rassatslla
carrlzalensis Harks, sp.
Nov.
(Plate 3, figs, 3, 6, S)
Baseriptioa (based on holotypa and f paratyjpae ):
shell moderately large, sub-ovate, moderately convex,
with low, posteriorly inclined beaks and large posterior
dorsal area. Hatlo of length to height {adult specimens)
4*3, of length to convexity (both valves) 2:1.
Posterior
margin truncate, nearly straight; posterior dorsal margin
89
iJmbones raoderately convex, rounded toward the
straight.
small beak.
Beak inclined anteriorly, somewhat flattened,
with the flattened surface orthogyral and marked with concentric undulations, about 10 oa the first five millimeters
from the beak to the apex of the umbo,
Lunula .moderately
sunken, about 2.0 to 2.5 mm. below the dorsal shell sur-
face, ovate, larger in the left valve.
Escutcheon narrow,
moderately deep, broader in the right valve, extending
about
2/3
of distance toward posterior extremity Qf
area,
concentric sculpture of about 10 modulatory ridges from
beak to apex of umbo, then Irregular, fine growth striae
ever tne rest of the valve, and raised, sharply rounded
concentric ribs on the anterior third of both valves.
'Pos-
terior slope broad, separated from main part of disc by a
low ridge that diminishes toward the ventral margin. Hinge
not seen.
Pallia! line entire, sharp anteriorly, indis-
tinct posteriorly.
Muscle scars deeply Impressed. In-
terior of valve with a low, vertical ridge extending from
Just
before beak cavity to pallia! line.
Variation noted
in one Immature specimen, which is more elongate, with a
more sharply rounded anterior margin than full-sized in-
dividuals. Dimensions of holotype: _ length 56,0 urn.,
height 43.4 MS*, convexity (both valves, one slightly
crushed) 27
ism,
Estimated complete dimensions of figured
paratyps (both valves):
convexity 29.6
mm.
length 56,3 ma., height 42.0 on.
,
90
This species is unlike any other tropical ime-rleaa
slope
**'
and
**
lucressatelle because of its broad 'oostsrlcr
mnimtmimmw.mkmmMim.ttmi nw u:m#*mMm<wmm-
the crthogyrsl
ana
oplsthogyral slope between beak
instead of
in its broad poster!©*
umbo,
it resembles the Austra-
lian living Sucrebsatelis } .^a^cola Lsnsrok, which, however,
n-
has s rounded, erect beak, whereas that of E. carrizaleT
sl.s is fl&ttened. Because of the somewhat flattened beak,
.
.
be
I* carrl,anion. els should, perhaps,
«.
MM.
npnppin»iriiil..»
milinnIt mm iHi.nn
ii,.»
«,.p. .»-.»■»»
■
*.
assigned to the sub*pW>
—
139); but the type
(1930,* p.
*
genus Hybolophua
of
» .ni.miiiniM.Mii. Stswsrt
,**
vp
'«Kiip.i,i.i
P W
in
"W
tlybolophus , jf. gibboaa sowarby, has a very different shape
and a strongly oplsthogyral slope from beak to umbo.
1* carrlzalenals occur* at several localities of
mm '
ilmi..'iiuiippr
miam-iMPmm mi fwiiK iiMM-Pin-i*
the Lower Miocene subibaja
**
ar@
Seonsla sp,
formation.
Associated with
, Turritella con^ulstadorana, and
lnclna of " C. saohura.
The trivial
urns.®
Cavi-
is taken from the
village of Carrlasl, which is loeutsc several kilometers
southeast of the localities whore the fossil occurs,
Materials holotype no, &Q419, Paleontologies! Eesosrch institution, from locality I.P.C. 11120, near the
village ol
Oarrlial, northern rro&reso Basin.
no. 20420 (figured) from locality I.P.C.
Paratype
11037,
Paratype*
no. 20421 (five specimens) from locality 11037.
gucrassateila avlagnanala pcrniana olsson
peruviana
olsson, 1932, Bull.
'
gucrassatella aviaguensls
'
,
Paleo.,
fig*
§17
Amer.
wt la
&» pp. 86-07,
C
91
*Our shells from the Lower Miocene
mation, here called Middle
Sechura
*
/leru/
Miocene/
/progreso
for-
of icuador and
1
are so close to avisguensls F. Hodson
mmmmrnm'**<mm^mmm ■*■>w.*.«*-»^***MiiHiiM#>***^
—
1927, Bull. Amer, Paleo. , vol, 13, p. 43, pi* 28, figs.
4, 7, 8, 10.
** *"****"*** mmmmmm "**
m. mm
***-*n*
m* "*» *m*
**fc
i
*s* ■■*
n» <w*nr ■**
m*
*■*_"«*
'*» ■***">*«" ****"!*
"»
*■" .^- 4*
it i»
mi* *r* w.lmt
mt 1t"Hf ft wfr w «■*> .****"*«
from Venezuela that they can be considered no more than
a subspecies* (olsson, loc. cit.).
Material;
10 specimens from locality I.P.C. 508,
type Progreso formation south of Progreso, Guayas Province,
.Ecuador.
Family Lueinidaa
Genus Lucina Bruguldre, 1797
Type (by subsequent designation, Anton, 1839),
Venus pensylvanica Lixm#, Becent, Caribbean 3ea,
'n I Willi
I
II
,
IW>r>liiiii|i'iriiili«lUll«plriii| HimMiPp«.ipi»HiHim.i llium
Lucina Lamarck, 1801, type
i»
L,
Jamaicensis Lam.
pectinate (Gmalln)}, is a homonym of Lucina Bru-
gulere 1797.
The first valid designation of a type for
Lucina Bruguiere is that of Anton, 1539, who cited Venus
pensylvanica LlnnC with correct reference to sruguidra f s
plate 284, figure 1.
Schumacher's designation of Venus
pensylvanica Linne as type for Lucina Lamarck has no
nomenclature! status because it Is a needless re -assign*
saent for an invalid generic name with already designated
type.
92
The status of some of Bruguiere's noaes, especially
Lucina , Is still soot.
Venus pensylvanica is here taken
for the type of Luc lns because its designation
.most closely to the rules of nomenclature,
names used in the present
pap^tr
conforms'
The generic
are accompanied by men-
tion of the type species,- so that, regardless of noaeaclatural problems, the. reader may know the actual group of
animals that the writer Is considering.
Qsmls iAiqlnoaa Ball, Ifol
Type (by original designation), Lucina fileas stlmp-
son, Beeent, east coast of iorth America*
Luoinome: is distinguished from other luclnlds by
its relatively slight convexity, regular raised concentric
lamellae, feeble anterior teeth, well-marked posterior
cardinals with 2 and 4b bifid, and nearly straight posterior dorsal margin*
Lucino»f sp.
(Plate 4, fig. 1)
A single specimen
from the subibaja formation, Lower
Miocene, is referred to Luclnoaa because of its regular concentric lamellae, Lucinoma-like outline, m& rather thin
hinge plate.
showing a
The worn right valve hinge Is partly exposed,
worn central area that may have supported cardi-
nal teeth, a thin posterior lateral that extends half-way
to the extremity of the hinge line, and a narrow Internal
93
groove for the resllluia.
The lunula is elongate, narrow
and. Impressed, extending more than half-way to the anterior
extremity of the dorsum*
£" snfula^i Eeeve
The specimen Is somewhat similar
of the west coast of forth America*
differing from L. annuls ta in feeing more inflated, smaller,
and having a narrower hinge plate and less prominent flex-
ures of the posterior and anterior dorsal
areas*
The in-
terior of the specimen is not visible, Mmensionst length
19,0
aaa., height (estimated complete) 16*3
Lueine^a
ss_»
is predominately a temperate or eeld*«ater
genus, and for that Additional reason the specimen from
locality 11203 Is classified as a Luc i
noma with seme doubt*
It is associated with Arehltectonics nobllls, Conus roigl,
Megasurculs guay&aensla,
Carols
vaoingeni,
etc., in a
matrix of silts tone or fine sllty sandstone.
Materials linotype no. 20422, faleontologies! Sesesreh
Institution* trtm locality X»?*€* 11205 in the Las Htsas
sector*
Genus Luclnlsca
Ball*m 1901
SSHSMMp
■ ■
"li'mwi.ir
'
Type (by original designation) I»elas n&ssula, Conrad,
Pleistocene and Heeent, eastern United States and Cuba.
Bsbitat 7-200 fathoms, and also in shallow water*
liuelnisea
sp*
(Plate 4, fig, 3)
Seven specimens, the largest £0.3
wis.,
long, were
found at locality 808 in the type Progreso formation, Middle Miocene*
The exterior layer of shell is missing frost
most specimens* including that figured. The exterior sculpture,
94
worn* where studied, appears to be a subdued version of
the underlying pattern, as shown In the figure*
hinge Is not known*
Hi
Dimensions of figured specimens
length 19*3 mm** height 17*3 ski** convexity (rlgfct valve)
4*o
set.
Hypotype no* 20423* falsontologieal lesaarch fa*
stitution*
Gaaus Osvilueliia Fischer, 18&7
type {by moaotypy)* ftaeina sulcata La»rek
t
Bsrtoal&n (Boaane)*, Frmnce*
The distinguishing features of the
Ctoav&n* 1958*.
p*
gsiras,
teste
114. ars feeble relict teeth* s deep
lunula sunken banes th the basks, and a smooth margin,
Chevan divides the genus Into the following subgenera!
Ifonlttlors Xrsdale*m
Smith, Recent *
:,nmmmm
1280*
type mmmwm*KmmoHtmm~miim:
Lor!gas .ramaayl
mm%mirmmmmmamii-\mm'-
■
Csvllueloa, s«s«
Barblerella Otmwsn, 1938* type iMcins b&rtolerl
Dsshsyss, Paris Basin.
Begophyseiia Stewart, 1930, type
fiiclna
acbramml
Crosse, assent* West ladles and lloridsu
Subgenus Begophysams
Stewart* 1930
Type (by original designation ), Xiuolna sehraiatl
Crosse, Ressnt, Florida*
Pegopfayaame was created by Stewart for shells of
the group "foslaa sdemtuls,11
Be chose L» aehras»i as
95
type because it was well figured and its type still ex-
tant (1930, p. 180),
**Jk* (J.* )
from the
He states?
schraiam! appears to be distinct
smaller 'Carnibbean
edentula (Linns!...
species, L. (P, )
(loc. cit* )
fhus, if Stewarts concept
were adhered to,* Pegophysema
W .
BirnwiTWtiiMifßuip.i.T.nn
would be synonym!zed with
W
m.-p.
ppjm.i
modontia Link,' 1807,* which has
IPIIIPW.H..
■PI'I'.'PI.PI*!! II
1.1111l
as type Venus edentula LinnC
edentula w of the Caribbean is actually
0
Lucina chrysostoma Phillppi (Ball, 1903, p. 1354; als©
under
Anodontia of this report). Both
.
see
sphrsmnl
and "Lucl-aa* chrysostoma have salient,' elongate
nymphs
***
** "**
y^..up..,.,..
.p »..»p
i»„ in,i
u,»JTt,i. ...p^p...
,p ;nn iiiinlmiMii— lt
that support the ligament and well-defined lunules.
These
are features that are lacking on Venus edentula Ll%m4 of
the Indian Ocean, both according to chavan (1938) and to
my opinion of a specimen labelled Anodontia edentula (tinn^)
from the shores of the Had Sea, no, 35764 In the Stanford
University Conchological collection*
lith some hesitation, I
follow Chavan In placing
the subgenus ge*gophysema in the genus Cay ilucina, the type
of which Ihave not seen.
Superficially, Lucina schramml
Crosse varies but little from the
smaller Anodontia
eden-
tula (Linne); the principal differences are In size, definition of lunula, and strength of nymph.
However, it.'
Chavan has done an admirable service in tracing the lineage
of the lucinids; his work is nomenclaturally sound, and I
am not inclined to depart from his decisions.
96
AS noted by Chavan (1938, p, 119), Pegophyseiaa
Stewart Is distinguished by the following characters:
shell globose, regularly rounded, simply adorned with
fine growth striae; lunula clearly defined, .depressed,
salient toward the interior; hinge plate flat, straight,
elongate, with traces of tooth 3b not perceptible; ligament not sunken, on a thick, elongate nymph that Is salient posteriorly and parallel to the margin.
.
C.(P.)
soma» ) cf, mm.
sechura (Olsson)
*
*
*
Caviluclna (Pegophy
'mm
wimipii
n .,„.,p...
p.tjiini
»
~w*.pw>a.ipipi<,itiii!np..ijTiiiiiiiiiin. ii .1 1
IiiiiiuMi
.oi.-pppphwiu lii-j.-i.nw)
(Plate 4, fig, 4)
(geggphysena) seohura Olsson, 1932, Bull.
Paleo. , vol. 19, p. 91, pi. 7, figs. 6, 8.
C£* Lorlplnus
jyaar,
fhis species is one of the most eowmnlf occurring
forms In the Lower Miocene strata of the Progreso Basin.
Xt appears to be identical with Olsson *s species from the
MiddleMiocene Hontera formation of Peru, but is not so
called because actual specimens of C. sechura are not available to the writer for comparison,
.
of C. cf
C. sechura are rare,
fell preserved
examples
fhe hinge of one specimen
Is figured to show the narrow, apparently edentulous hingeplate, similar to the hinge-plate of the living C. (Pego-
—..
.
.
type
physema)
' Schramm!
(Crosse),
""" * of Pegophy
*
*
sema
,
m»
iiiiiiiiinniW.li
aTiim
..mm.
■tL,...,V
m
ii»i
»
mi.
p.p.
...pipu
■.
ilWi p inn
in in
ai
>,
The Bcuadorean species most closely related to C.
cit.)
'wmmmmm
cf. C. sechura Is C. * thalmannl (q.v.), Olsson (loc.
mtm
,n.nriiiir ■■
in. iii
ir r
""'t
mm*-
mm*mm\mmtmmmmmtmmmmmmmmm
mmmmmim
believes that C. sechura is closely related to "Lucina w
97
l.nca from the loeene Chira shale of Peru. If this Is
.
—
correct, a lineage may exist of "Luolna* lnca--C
sechura- 0. thalmannl— C.* densata (Pliocene)— C. edentuloides (Pliocene? to Hecent).
Material: hypotype no. 20424, Paleontological Besearch Institution, from locality X.P.C. 11037, west of
Carries!, northern Progreso Basin.
Further specimens
from localities 11037, 11091, 11093, 11200, etc.
Cavilucina ( Fegophyaema) thalmannl Marks, sp. nov*
(Plate 4, fig. 9)
Shell orbicular, of moderate size, inflated.
Lunula elongate, shallow In right valve, impressed, broad
In left valve, sculpture of fine, close-set, low concentric lamellae and underlying, barely perceptible radial
striae. Dimensions of holotype (a left valve): length
47,0 mm* t height
39.a mm,, convexity 13.0 ms.
specimen in the collection la 47,5
C.
mm*
The largest
tall.
thaliaannl is larger than JS. sechura (olsson) from
the Lower Miocene and smaller than 0. densata (Ball and
Ochsner) from the Pliocene of the Galapagos Islands.
It
further differs from 0. densata In having a less wavy
lunular area and a less indented, less sloping posterior
angulation.
identical.
The hinges of 0. densata and 0. thalmannl are
The Recent Gulf of California C. edentuloldea
98
(Verrill) x is very sisilar to C. densata and may be the
For the synonymy of this species, see Hertlein, L. 0.
and strong, A.M., 1946, Zoologies, vol. 31, pt. 3, p.
117 (as Anodontia).
northern representative of a stock that Includes the
species discussed above.
fi* thaliaannl
occurs in the
slltstone** member
of the Daule formation, Middle Miocene of southwestern
Ecuador.
Associated with it are at chiteoton!ca aexli
nearls cerusea, Katioa fflppyana ,
altillra, etc.
The species is named for Dr. Hans 3« Thalmann*
Material: holotype no. 20423, Paleontologioal Besearch institution, fro®
locality I.P.C. 1223, north of
Pa Jan, Daule Basin, Ecuador,
Paratype no* 20420 from the
same locality.
Paratypes
locality
1227, adjacent to 1223,
1,P.0.
no. 20427 (five specimens) from
Paratype no, 7973,
Stanford Univ. Paleo. type coll., from locality 1223,
Gsnua
Afiodontla Link, 1807
Type (by original designation),
Modontia alba Link
(a
Linne),' Becent,' India,
*
Venus edentula
mm
»p»pipi.
...p.pi
in
vi
i..
i
Chavan notes t.hat jnodontia differs from pegophyseaa
»n.
iiiiiiiiii.il
»«ppp^pip.»p.i. « vi... ,i,i.n.pi iipi.ii miiiii.
i
iiiirp.ppppiftp»p.,.ir.
mi
Stewart in having the ligament not supported on a salient
njmph (1938, p. 121), whereas In Pegophysema , as exemplified
.
ky Cavilucina (P. ) Schramm! , the type and C
(P.} chrysos-
99
toma of the Caribbean region ("Lucina" edentula
auctt.),
* *
m
■ii
I"
ll
n
ll
ii
phi
lilniiii
in
in mil
the ligament is supported by a strong nymph that extends
posteriorly nearly to the margin.
Anodontla stainforth! Marks, sp. now*
(Plate 4, fig. 8)
Description (based on holotype and two paratypes):
shell of moderate size, inflated, Inequilateral, Umbones
low. Beak small, prosogyral. Lunula elliptical, barely
defined, equal In both valves.
No escutcheon.
Sculpture
of low, uneven, concentric folds with minor wrinkles.
Pos-
terior faintly marked off on both interior and exterior of
shell by two or three shallow radial furrows.
Hinges of
both valves very slight, with a thin nymph rising from
the
posterior at an angle of five
degrees to the dorsal
margin and terminating against the margin just behind the
beak, joined ventrally by the posterior extension of the
anterior hinge margin below the point of
termination. No
teeth detected. Posterior adductor scar just above posterior extremity of valve. Dimensions of holotype: length
(nearly complete) 47,8 mm, (estimated complete) 48,3 mm,,
height 43,0
mm*,
convexity (both valves) 27.7 mm*
of largest topotypa 55.4 mm*
Length
shells reaching a length of
75 mm. occur at nearly equivalent horizons in the Progreso
formation to the north of
Progreso
(localities 787, 7300-A)*
100
The new species is placed in Anodontia because of
Its small, edentulous hinge and thin, oblique nymph.
The
sculpture is uneven like that of Anodontia phllippiana
(Beeve), living in the Indo-Pacifle.
The new species dif-
fers from a* phillppiana by being slightly less inflated,
less prosogyral, and having the nymph slightly less oblique.
Of the described Miocene species, A. globulesa. (Deshayes),
Aqultanian and Burdigallan of France, Is most similar to
A- stslnforthi;
its hinge is perfectly analogous, but
slightly thinner, the sculpture is less uneven, and the
umbones are broader.
There are no published records of
anodontia for the tropical American Miocene,
The new species occurs at locality I.P.C, 308, south
of the village of
Progreso,
upper Progreso formation, Middle
Miocene of southwestern Ecuador, and at scattered localities
of equivalent horizons elsewhere in the
Progreso
Basin.
Material: holotype no. 20425, .Paleontological Research Institution, from locality I.P.C. §08.
Paratype
no.
20429 from the same locality. Paratype no. 7974, Stanford
Oniv. Paleo. type coll., from the same locality.
Family iryclnldae
Genus Sornla Phllippi, 1836
Type (by subsequent designation, Stoliozka, 1870),
Bornia corbuloldes Phllippi, Becent, Mediterranean sea.
101
Subgenus Temblornla Keen, 1943
Type (by original designation), Donax triangulate
immMinmmmmmmmtmmmmmmm
mmmmm*mm
TMmnmmmmi
Anderson and Martin, 1914, Miocene, California.
*
***
Bornla (Tembiornia)
keenae Marks,* sp.
Nov.
m&mmwmmmmimmmm
■**» mmmm*m<wm>mm
■>■minnnm ■< **mmm<
w
M.i^,*.imiwji:
i*mmm**mm>
(Plate 4, fig. 3)
Description (based on the holotype, a left valve
with the anterior broken): shell small, subtrigonal,
moderately inflated, nearly symmetrical; height
length; convexity
Bs£
of length.
70fl of
Ventral margin with
slight central embayment, probably indented by radial
sculpture*
Beak small, barely inflated, of whitish,
translucent material.
Hsdlal sculpture restricted to
regions of juncture of central with anterior and pos-
terior slopes, consisting of about six low corrugations
on each ridge, strongest at margins.
Concentric sculp-
ture lacking, but growth traces shown hy color bands*
Hesilifer interior, probably snail and shallow*
Left
valve hinge with a strong, protuberant, subtrigonal anterior cardinal tooth, a moderately strong, thin posterior
cardinal, and a strong, thick posterior lateral; hinge
plate entire, with ventral margin nearly straight " in*
terior not seen, probably integripalllate and crenulate
at
intersections of posterior ana anterior margins with
ventral margin. Dimensions of holotype: length (incomplete), 6.4
mm* i
mm*;
estimated length, 6.7 mmE* height, 4.7
convexity, 1.7 mm.
102
1
The subgenus Temblornia Kemn,w 1943 is distinctive
*m m> *m mm mmmm- mmmm*m mm mmmmm* mmmm mmmm-***» mm mm mmmmmummm mmmm m*
,
—
m «a
«*
-* «**»"
mum
**-*». "*«****» mm mm mmmm mm mm»m m *m *m4m mmmm
I
Keen, A. M* New Mollusks from the Bound Mountain silt
(Temblor) Miocene of California, Trans. San Diego Soo.
Hat, Hist., vol. 10, no. 2, pp w 23-60, 1943.
**«w**(Ni»*»'#i.**»*,«ii..i>«*ii^,,,»
for Its limited raaial sculpture, entire hinge plate, and
strong dentition.
Its three known species are restricted
to Lower and Lower Middle Miocene deposits of the lest
Coast of America.
Bornla (Temblornia) triangulate (Ander-
son and Martin), the type, occurs in the Bound Mountain
silt of California.
A
second undescribed species occurs
in the lowermost Gatun formation of Panama.
B. keenae
is higher, more inflated, stronger flexed on the ventral
triangulate,
than mmm
B. ivmmum.
margin,* and has a higher hinge
"*
-mmmmttmwSmmmmmm^mmmm^v
».-■
B,
mm*
keenae has about the same shape as the species from Panama,
but has radial sculpture of about six relatively widely
spaced, raised folds, whereas the species from Panama has
about 12 very fine radial folds over the same area*
.
The only occurrence of g keenae is In the subibaja
formation, Lower Miocene of Ecuador, 1408 feet above the
base of the formation.
The fauna associated with mm.
B. keenae ineludss
—I.M.—W.
Nuculana sublbajana, ffoetla aacnelli and Telllna sp.
These species, together with the silty and sandy lithology
of the enclosing rock, indicate a shallow ncri tic-zone
103
habitat in an ares of rapid sediiaentatlon. The species
is named for Br* A, Hyrs Keen*
Holotype no. 20430, Paleontologlcal Research In-
stitution, from the Zacachdn corehole, depth 430-469
feet,
Family Cardlidae
Genus Plnocardlua Dall, 1000
Type (by original designation), Cardlum magnum
Born, 1778 (not Linnd, 1738) («
C,
rebusturn Solander,
1786), Becent, Oulf Cosst of the United States*
Plnocardlua ecuadoriale (Olsson)
CardluM (Blneeardlum.) ecuadorislis Olsson, 1932, Bull,
Amer* Paleo. vol. 19, no. 68, p. 97, pi* 8, fig, 1.
,
Clsson originally described this species from
material he obtained in the present type section of the
Progreso formation, Middle Miocene*
He also recorded it
from the Upper Sorritos formation, Lower Miocene of Peru.
In leuador, P. eeu&denisle is represented In the basal
stratum of the Progreso formation by a single specimen,
and occurs rather commonly throughout the remainder of
the formation* It is also found In the
tt
,,
Basal oalcareeus
and "Upper calcareous* .members of the .Paula formation,
Material t
specimens from localities I.P.C* 7618
(basal bed), 7498 (Zaeaehdn section), 507, 508 (type Pro-
greso formation).
104
Superfamily Veneraoea
Family Do sini
ldas
a Scopoll, 1777
Cenus Dosini
Type {hf monotypy), Chama. dosin Aden son ( s Dosinla
afrlcana Hanley), Hecent, western Africa*
Subgenus
***
Soslnldla Pall,* 1902
mim*smm*mm ■
Type (by original designation), Venus coneentrica
Born, Pleistocene and Becent, Oulf
of Mexico.
Doainla (Poalnidla) dellcatissima Brown and Filsbry
Pqslnla dellcatissima Brown and Filsbry, 1912, Froc, lead.
Hat, Sci.''""Philadelphia , vol. 64, p. 516, pi. 26, fig, 1;
Anderson, 1929, California Acad. sei. f ser. 4, vol, 18,
p. 166; Hoffmeister, 1938, 801. Qeol* y Mia. (fenesuela),
vol. 8, no. 2-4, p. 109 (list of La Rosa formation fossils)! Sutton, 1946, After. Assoc, Pet. Geol* Bull*, vol.
30, no, 10, p, 1693 (list of La Boss formation fossils)*
Sosinla (Doslnidla)
'
'
dellcatissiaa
Brown and Pilsbry,
Spieker** TlSF^ohhs Hopkins tin!v, Studies In Geology,
no. 3, p. 140) Banna and Israelsky, 1983. Proc, Calif.
Acad. Sci*, ser. 4, vol. 14, p. 63 (list); Palmer, 1927,
Paleontograpbioa Americana, vol. 1, no. 5, p, 63, pi, 17,
figs. 1, 9 (Oatun specimens) |Olsson, 1932, Bull. Amer.
Paleo., vol. 19, p. 103, pi. 9, figs. 3, 4, 3. (Figure
3 is from the Lower Zorritos formation of Peru; figures
4, 3 from the type Progreso formation of Ecuador.)
The hinge of a specimen from the type Progreso for-
mation, Middle Miocene, is very similar to that of the
living species p. dunkeri Phllippi, differing from the
latter mainly In the lesser arch of the hinge plata.
largest Progreso specimen is 61 mm. tall*
The
D. dellcatissima
has a geographic range from Peru to the Caribbean, and a
stratigraphlc range from Lower to Middle Miocene, with
moat of the specimens occurring in Middle Miocene strata.
105
Material: specimens from localities I.P.C. 308 and
529 (type
progreso formation, Middle Miocene), 7498
(pro-
greso formation), and noted at locality 11201.
Family Clamentlldae
Cenus Olamantla Cray, 1837
Type (by original designation},
Gray, Hassat.
.Venus papyracaa
indo-Pacifle*
Subgenus dementia
s.a.
*
*
Cleaeatla (dementia)
dariena (Conrad)
hii >iw11*11*1 *«.i,ifiiiii«i- m*,*HwwH.mmmm*
mvmmm**mw mmm»'->*mm
Msretrix
dariena Conrad, 1833, o*3. Pacific U.K. Sxpl. ,
"'""
voT7~s , pfT"f, Appendix, p. 328, pi, 6, fig, 53 (from
Gatun formation, Miocene, Panama).
Olsson has given the synonymy of this wide-spread
species (1932, p. 102),
dariena dariena was widely distributed
**£*
along iSte' so:utlHatiT'west edge of the Caribbean Sea during lower and middle Miocene time
mil also 1» the eastern Pacific from Peru to
Costa Hiea*«*lt has...been recorded from
Brazil, Trinidad. Panama, Costa Pica, and Peru,
and records are her© given for Venezuela, Colombia and Ecuador, Middle Miocene deposits carry
the largest shells. 'Virtually all the specimens from lower Miocene beds are relatively
small and grade almost imperceptibly Into c.
dariena rabelll** (foodring, i. P.* American"
Tertiary Mo Husks of the Genus Clement la
U.S. Oeol. tjurv. Prof, Pap. 147, 1926, p. 33),
J
'
.
In Peru,
c. dariena dariena
ranges throughout the
Miocene section (Olsson, op, cit,, p, 103).
In the Pro-
greso Basin of Beuedor it occurs only in the Middle Miocene
Progreso formation, where it attains a large size,
men from locality I.P.C. 389, near the town of
A speci-
Progreso,
106
is 72 .mm, tall. Both valves of specimens are coiasonly
found together in fine silty sandstone, indicating that
the shells were interred in their natural habitat*
aood-
ring (op. cit,, p. 30) suggests that the shells remained
buried in the mm& or fine sand .in which they burrowed
while alive.
Materials locality I*PE* 329 (two specimens),
locality 508 (two specimens), Progreso sector. Localities
1459 and 1464.
Family Meratricidaa
subfamily Pitarl
nae
Casus Pitar
Burner, 1837
Type (by monotypy), Venus
tumen^ Gmelia,
Recent,
lest Africa,
Pall, 1902
Laaalll.oonchji
Subgenus
...,..,.
*"*i»«p..~,pi.'...
■-.'".p
"■
i„in«.i»
»
type (by original designation), Cytherea coneiana
Sowerby, Recent, west coast of tropical America.
Fitar (LaaelliconcM) thompsonl Murks,
»p*
nov.
(Plate 4, figa* 6, 7)
Description (based on the holotype and five paratypes):
shell of moderate size,
alongate-ovata , moderately
inflated, strongly prosogyral, with beaks at anterior one-
third; slightly truncate posteriorly, slightly emarginate
on the postero-ventral margin*
Lunula short, &*pr*&**& 9
ornamented with' about five low, round- topped ribs.
107
slightly convex on upper margin.
Escutcheon deep, narrow,
reaching three-fifths of distance from beak to posterior
margin (measured in vertical plane),
sculpture of con-
centric, lamellar ribs, sharp-ridged, concave dorsally,
flat ventrally, with a tendency to curve over ventrally,
especially on the anterior and posterior portions, closely
spaced on umbones with about three fine concentric striae
on interspaces, wider spaced ventrally with smooth or
barely striated interspaces, numbering
6/3
mm,
on center
of disk, each alternate rib or two of three ribs submerg-
ing on anterior and posterior margins.
Hinge rather nar-
row; left valve with a strong, sharp-topped antero -lateral,
a thin anterior cardinal (2-a), a moderately heavy central
cardinal (2-b) joined to 2-a to form an inverted V, and a
long, slender, obscurely bifid posterior cardinal (4-b).
una,
The left hinge compares closely to that of P. conel
differing in its stralghter margin and more erect central
cardinal tooth. Study of the six type specimens shows no
appreciable variation in any feature. Dimensions of holotype: length, 33
mm, |height,
26 mm.; convexity (both
valves), 17.3 mm.
The hinge of P. thompsonl has the same features
MMM*
mutrtminm»imM»'iimmimmmmmmmmmmmm
as the Recent P. concinna of the west coast, and strongly
accentuates the aubgenerie relation that is indicated by
the sculpture and shape.
P. concinna differs mainly in
108
having rounder, non-lamellar, bifurcating ribs and longer
lunula. P.
alteraatua. Recent,
Is a
hitter shell, but has
the same type of ribs as the mw species; they are, how-
.
ever, somewhat more erect than those of *****
thompsonl
P. mmm*m
The
\m*>*X&<>m<-m>m,mm-<mm
■
most closely related fossil species are possibly P. pater-
sonl (olsson) from the Lower zorrltos formation of Peru,
whlch differs in its greater height and more erect concen-
tric ribs (the hinge
is not kcown),' and P. aff. mm
P. ,thomp,..,,
m
P-
.mm
i«,^n
son! (q.v.), which is described on following pages,
—
ugllipi
P.
**
acutlcostata (Gabb) from the Dominican Republic is sp*mm».wf,i<*>*»m.mm>*mm
?
parently also a related, species, having the same type of
sculpture and same general shape, although the shell Is
higher, the posterior angulation less distinct, and the
ribs closer spaced (8 per 3 mm. instead of 6 per 5 mm, ) #
£*
thompaonl
occurs in the lowermost strata of the
Gatun formation, from 10 to 110 feet stratigraphlcally
above the base of the formation about six miles
east
of the city of Colon on the Boyd-Boosave lt highway, He-1
public of Panama.
The species Is described herein
gN*»»*»
mmmmmmmmmm«mmmm mmmmmmmmm* m«... »»»* mmmmmmmmmmmmmmmmmmmmmmm
For notes on the stratigraphy and fauna of this area,
see Kmn f A. M. and Thompson, T. P., notes on the Gatun
formation (Miocene), Panama Canal sons, Gaol* Soo. Amer.
Bull., vol. 37, no. 18, pt. 2, p* 1260 (December, 1946).
because of Its close relationship to a form from strata
directly below and above the contact between the Subibaja
(Lower Miocene) and Progreso (Middle Miocene) formations
109
of southwestern Ecuador.
The acuadoreaa species is de-
scribed on the following pages.
Material: holotype no, 7 973, Stanford Unlv. False.
type col!*, from locality L.s*J*U. 2611.
7976. (figured) from locality L*S«?«tf.
no.
faratype
2633,
ao*
Paratypes
7977 (three specimens) from locality 2611,
Paratype
no. 20431, Paleontologies! Besearch Institution, fro®
locality 8611,
Collector, T.
y*
Thompson, for whom the
species is named*
) thompsonl Marks
' aff. P. (L.
*
Pitar (Lamelllconcha)
*
*<«"
.1- in, mi .»
iii.api.ip.
~~»
mmm*mmmmm
mm'
i
mSHm
The icuadorean specimens differ from P. tnomason!
only by having 6 instead of 3 ribs per 3 an* Interval,
less ventral emsrginatioa, and a heavier, more sculptured
escutcheons! ridge.
In other aspects of shape, type of
ribs, and hinge, the Icuadorean specimens are Identical
with P. thompsonl (_,v.)*
pita*
mmwmw-wmimpm'
"***
aff* P. thompsonl has a knois® stratigraphla
m#m
mmm>!>o^mmmm~mimmmm^mmm#m--
range of about 90 feet, occurring from 82 feet below the
top of the subibaja formation, Lower Miocene, to the basal
beds of the overlying strata, which belong in the Progreso
formation, Middle Miocene.
Material: specimens from the
g&eaehun corehole,
depth 140-130 feat and depth 68-71 feet, and from locality
1,P.0.
7618, basal
ters south of
Progreso
zacaohuk*
formation, about six kilome-
110
Pi tar (Lamelllconcha)- zaoachunensis Marks,*
mmmmmiMm mimtmm
mmm<M\ m<m>*>m* mm.mmmm»mmmm'm<<mmwm.wmmm'
.«i*M*»w^»iiiiMiw.M*ttiiiliiM^
4, fig. 1, plat®
(Plat©
sp*
***
nov.
3, fig. 6)
Description (based oa holotype and one paratype);
shell
rather large, compressed, elongate-ovate, with rounded
anterior margin, posterior truncation, and moderately high
umbones.
Lunula elongate-elliptical, Impressed, similar
—
of the Hecent fauna,*
'
to that of P. conoinnus (Sowerby)
m r
».»■»..,».,«„■.
.inn,
a
P»..1..,»M
decorated with about 20 low riblets.
unsculptured.
Escutcheon long, deeply Impressed, separated from rest of
valve by an elevated, sharply rounded ridge crossed by extensions of the concentric ribs, reaching one-half the
distance from beak to posterior extremity as scan in vertical plane,
sculpture of low, asymmetrically round-
topped ribs that are concave dorsally, barely convex ventrally, have virtually
no interspaces, and divide at rare
intervals on the disk, light valve hinge rather broad,
with the normal, complement of teeth;- two anterior laterals, of which the upper is small, the lower elongate and
rising to a central prominence; and three cardinals, of
which the posterior (3-b) is rather short and deeply bifid.
are broken off near their bases.
In the holotype, 3-a and I
Hinge of left valve not known.
reaching
57# of
Pallia! sinus pointed,
length of shell toward anterior margin.
Dimensions of holotype: length 43.0 mm*
convexity 10.8 mm*
, height 34.8 asa, ,
111
Pitar (Lamelllcencha) conclnnus (Sby. ) Is the
living form most closely related to p. .zac.aehunensis»
having the same general outline, type of sculpture, and
hinge features.
P, conclnnus,
however, differs in details
the palllal sinus is bluntly rounded and not pointed, the
ribs are rounder with wider interspaces and more divisions,
the shape Is slightly more truncate posteriorly and emarginate ventrally, the umbonas less prominent, and the
escutcheon longer.
Except for the differences In the
pallia! sinuses, the distinctions are barely more than
—
sufficient to separate the species, and it is possible
that P,
conclnnus is in the same line of descent as P.
*
zacachunensis.
Among the
fossil shells, P. ecu ticostatus
(Gabb) from Santo Domingo is superficially similar to P.
zacachunensis, but differs from It in having a smaller
lunule, more strongly lamellar ribs, and a rounded pallial
It is a smaller shell*
sinus.
P. aff. jP. zacachunensis
from the Middle Miocene strata of the Baule
Basin (q.v, )
** a direct descendant of mm
is apparently
P. zacachunensis.
*WmW
mmtwwm
-
<m*«?*>*vvm.mmM»
Ho intermediate species are known by which the hypothetical lineage P. zacachunensis
P. conclnnus can be traced
from Middle Miocene to Recent*
p, zacachunensis is known to occur only In the
uppermcst 72 feet of the Subibaja formation, Lower Miocene,
and in the basal 23 feet of the Progreso formation, Middle
Miocene.
112
Materials holotype no. 20432, Paleontologies! Research Institution, from the Zaeaehun corohole, depth
Paratype
130-140 feet.
no. 20433 from the same corehole,
depth 33-43 feet.
(Lame
Pitar
lllconcha)" aff,
mm
■ll
inmil
)i
'kiii.h
iin.ii«innn»ii minimum v riiinnnwi nn
P,
mm
Marks
zacachunensis
mmm
wnonmn;■
hw.ii.muMmim,.,,
n
1111111111.11111
The ventral one-half of the only specimen is missing.
The remaining characters are Identical with those of
P. zacachunensis, except that the lunula is more elongate
and the concentric lamellae on the upper portion of the
disk are closer spaced, measuring 10 ribs pm Shbu* Inter-
val,*' where P. zacachunensis measures 7 ribs per
*
S-xam. inmm*
mmmimmi\mmMmmmmwmmmmmmKmmmMmmmtmmm>
such features as type of rib, escutcheon, Impres-
terval.
sion and decoration of lunula, shape of dorsal portion, etc
are identical. The hinge of the left valve shows a thin,
triangular anterior lateral, a thin anterior cardinal (2a),
a heavy, obscurely concave posterior cardinal (2b), and a
long, very thin, low posterior cardinal (4b) barely aepa«*
rated from the nymph by a shallow groove.
Uhis species is very closely related to P. zacachunensis,
* and may well be a direct descendant.
urn—
.wm..,...,,,.,..,.,...,...*.ii .i mi
Its 5trati-
graphic position is considerably higher in the section,
occurring several hundred feet above the Daule Basin hori-
zon that is supposed to be equivalent to the Progreso Basin
strata where P. zacachunensis occurs.
113
Materia!f one incomplete specimen fros locality
148# f ftßlu«t siltstona** member of the Paula formation,
near Jerusalem* Daule main,
southwestern, Ecuador*
goi^ha)
Pitar ( Laa^a11i
sp*
(Plate 3, figs, 4, f )
T» poorly preserved specimens of a concentrically
locality
sculptured
*
** §0©
Pitar
iilipiiilii
iiiii>»iii)|B>ii wart found at
Profres© formation, Middle Hlo#a»,
of the typa
wm
The binge of one Is
pitarisa* with the left valve laving a strong imtarior
lateral and the two cardinal tenth in tha form of an In*
verted f ;but an exceptionally strong aptfb lias oblique
to the gtiMriMKrlar^araal hinge snargla.
Preservation is
too -poor to warrant description as a new species,
tha
better specimen useaaufaai length 33*6 sai* , fcaight 86*4
us*, convexity (both vulvas)
XW«B
m*
i^potypaa mo,
80434, Paleontologies! Isaearall Institution*
altar iPltarella) gatuaaaala multifllofue (Sail)
(Plate §, fig, I)
Callocardla (gatunanala variety) gultiflloaa Pall, 1903,
traia* i^^Slnst* sol*, mTl7p»« ®» P» M»l»
pi. 34, fig* 13*
Pilsbry*
multlfiioaa Mil, Brown, and
Callocardla naiuneiiais
*
TRnXT«fSa; lead. Hat* sol. Philadelphia, vol,
63,
"iSm^m^m'',mmSmmimmitm *R*
3j£*
,«"»«..
*»
370*
Callocardla „»tunane!a Pall, olsaoa. 1988, Bull, mm*
Palaai, vol^ 9 p* 383, pi* 38, fig* 1*
,
114
gatunensls
Pitaria (Pitarella) mmmmmm
multlfllosa (Ball), .Palmer,
"
1926, Paleontographlca Americana' vol. 1, no* 3, p.
244, pi. 7, fig. 6.
"m'tm<&itnM&m*mmmmm!mm
■
mmtmm^mmv^i'^wm*n'*«».»
« *.jfw*■■wwnwi*w
mmm
i«.**ww»*#
mmmmmmm*mmmmmmmmm^m^mmmmmmmmm-
A single specimen was found at locality 1227 in
*
the "Blue siltstone1 member of the Paula formation, Middle
Miocene.
The references cited above note the occurrence
of the subspecies in the Middle Miocene beds of the Qstun
formation, Panama, in the Oatun fomation of Costa Hica,
and at Ponton, Santo Domingo {fits Ball, loc. cit,). Hypotype no. 20433, Paleontological Research Institution.
Pitar (Pitar) aff,
P,
consanguineus (€. B. Adams)
A few poorly preserved specimens comparable to the
Kecent j?, consangulneus were found at locality
in the
Progreso formation,
the same general shape
,
Middle Miocene,
I,
P.C.
They
308
are of
size, and sculpture as p. consen-
slightly
guineus,* but differ from the Hecent form in being
vtar
m
■X.i
i.ip.pM.
mor©
tumid, less extended anteriorly, and having a slightly
smaller lunula.
height £1,9 mm,
A
small specimen measures s length
, convexity
specimen is 29.0
ma. long,
(both valves) 15,4 ma*
23,7 mm* *
a larger
24,8 mm, high.
Genus Megapitarla Grant and
Gala, 1931
Tjpm {hy original designation), Cytherea aurantlaca
Sowerby, Hecent, west coast of tropical America.
Shell like that of the typical subgenus
/pitar/, with similar hinge, shape and polTshed'"exterlor, but very much larger and
heavier**
(Srant and Gale, 1931, p. 346.)
115
Megagltarla
—
** ■
differs from -Macrocalllsta
Meek (type,
mmm>mm.
r n
,mmm:«im m,^Smmri,u««m m
ti
"m
in
r.i
Venus nlmboaa Solander) by being higher, thicker- shelied,
with a heavier hinge-plate In which the anterior socket
Is oriented parallel to the sloping dorsal margin, and
not horizontally; the posterior lateral is a moaerately
heavy bifid tooth, also oblique (not horizontal), and
causes a protrusion of the ventral margin of the hingeplate.
MSgapltaria olsspnl
Marks, sp*
mmm
.iii»lll..piip*iipiiip.p,.-ii.p»,»ipii,pp
pi
.winm i.i, ,p
i i
Ij,
r
■m*
nov.
(Plate 3, fig. 1)
Description (based on holotype and 13 paratypes),
shell moderately large, depressed, elongate-ovate; height
'
about
3/4
of length; posterior area distinct, Unbones
rather low. Beak small, pointed, prosogyral.
Lunula
large, elongate, barely defined by low ridge. - sculpture
irregular, of shallow Incised grooves, accentuated by
erosion.
Posterior slope narrow, defined by a distinct
angulation with interfacial angle about 130 degrees on
mature shell.
Hinge heavy, pitarins; right valve with
anterior socket parallel to margin of shell, two thin
cardinal teeth, a heavy, bifid posterior lateral inclined
about 80 degrees from, horizontal and causing a protrusion
of the hinge margin, and a heavy posterior nymph that extends nearly half-way to the posterior extremity; left
116
valve apparently normal, with posterior cardinal thick*
triangular.
Ligaments! groove fairly deep.
features not known.
Internal
Variations noted in shape of shell,
The average height/length
older shells being higher.
ratio about 73%; a shell of length 34 mm* with ratio 72f;
a shell of length 67 mm, with ratio 76<;|j
abnormally high, with ratio
(a right valve)
13 ma*
j
length 33
80^.
the holotype
Dimensions of holotype
mm., height 44
mm,, convexity
Dimensions of largest specimen (a right valve):
length 67 mm., height 31 mm* s convexity 13
M* olfsoal
mm.
Is most closely related to the Hecent
west coast species J§. aurantiaoa
Sow,
and if, squalida Sow.
the hinge is large and heavy like that .of
M,
aurantiaoa ,
but the anterior socket is more closely parallel to the
dorsal margin and the cardinal teeth are. longer. M*
aurantiaca is a higher, more rounded shell with a wider
posterior slope. M.
sfuallda
differs from jf. olsson!
chiefly by having a narrower hinge and a higher, rounder,
more Inflated shape*
Ko species described as Tertiary
fossil from the .marl can tropics seems to resemble M*
olseonl.
MSgapltaria traftoni (Olsson) from the Pleis-
tocene of the Buries Peninsula (1942, Bull. Amer. Balee.
,
vol. 27, p. 38, pl. 3, figs, 2,3) is a very elongate form
with the distinct posterior slope of iiegapltarla and a
hinge like that of
if.
squallda*
117
-The stratigraphic occurrence of M. olsson! is in
the lower part of the Progreso formation, Middle Miocene,
geuador*
It Is associated with Dinoaardijom ecuadorlala ,
Sucrassatella peruviana
etc,
,
abrupta , T, alti
lira,
in a matrix of silty, poorly sorted sandstone often
containing fragments of other shells.
habitat is
indicated,
A ©hallo w-water
The specie® is named for.Pr* A.
A,
Olsson, the senior paleontologist of tha aouth American
Tertiary formations.
Materials holotype no. 20436, Paleonto logical Hesearch Institution, from locality I.P.C. 870, northeast
of the town of Progreso.
ity 734.
Paratypes no, 80437 from local-
Paratype no. 7978, Stanford Univ*
falsa*
type
coll., from locality 780. Further specimens from localities
I.P.C,
775, 783, 068, and 7618.
family Chionldae
Genua Chione legerle
yon
mhlfeld, 1811
Type (by subsequent designation, 'dray, 1847), Venus
dv.ssra Liana' (7
* V.
cancellata Linn*), Becent, eastern
Asterlaa*
Subgenus Chionopsls Olsson, 1932
Type (by original designation), Chione amathusia
(Phllippi) (* Venus amathusia Philippl), Proposed as a
section of the subgenus Ohiose, s.s*
Chionopsis as a section, he presents
Although olsson uses
a good case for its
118
distinction as a subgenus.
"To Chionopsis belong most of
the fossil and recent species of Chione and it represents
an older and possibly different line of descsnt" (loc* cit.).
*
* prppln&ua Spieker
"*
Chione (chionopsis)
1/*muiMm*mm\\*
mm
■ttztmmmmmT
*w,mtmm iw
wAmimmmm'-
tmm^mmmmmmmmmm ■
tmmmm
»mm"
■
j Chione ) propinqua Spieker, 1922, Johns Hopkins Unlv*
Chione
,'
"lludi@s '"in €mCjw*U 3, pp* 152-154, pi. 9, fig, 12.
Banna and Israelsky, 1923, iroc. California Acad, Sci,,
ser* 4, vol, 14, no. 2, p. 63 (list)*
l
l
Chione (Chionopsis) pronin9.ua Spieker, Olsson, 1932, Bull,
Set*
Palea*, vol, Ifc, no. 68, p. 112, pi, 11, figa*
,
2 3 8«
,
Spieker notes the similarity between his species
acd C.
wall!
Guppy from the Miocene of Trinidad.
notes also a resemblance to C* paraguanensla
Miocene of Venezuela.
Olsson
the
*"* virtually
*
C. prop.lng.ua
has a hinge
O.IIP mftiiliii imS*mmmm
mm.
p
11
Identical with that of the Hecent mmm
C. amathusia, the type
m
'
Q$
Chionopsis.
ttitmmmm<m-iMiwaKmwwim w'ntvwmiiw
'
#**>
In Peru, c. prosln_ue occurs in the Lower
Eorrltos formation of aapotal (Qleaen, op. cit., p. 113).
In scuador, the species ranges from the uppermost Lower
Miocene well into the Middle Miocene. Occurrences are
noted in the upper aaeaehun member of the Subibaja forma-
tion, Lower Miocene, the progreso formation, and the Pauls
formation*
listsrials one specimen from the zacaehua corehole,
depth 130-140 feet,
one fro® depth 140-130 feet, and one
from depth 33-43 feet; several specimens from localities
I.P.C. 7618 (basal Progreso formation), 7498, and 733
,
119
(Progreso formation); several specimens from locality
1134 (Daule formation, Basal calcareous" member).
f,
.
Cf
Chione
■iiiiiin*i^ii.riiMiii*pi>iwi
11*111*
j* Chionopsis)
'
tmmummmmmmm
■«*wiw.*«i*ii,wm».««iiii i
spieker! Olsson (?)
*
*
mm*ommmmmi<n.*ni»'i*im*w*iwinnwmr
Chione (Chionopsis) spieker lOlsson, 1932, Bull, Amer,
fig. 7, pi. 12, figs.
4, 5.
PaleoT, voTTTTTp. ll^V pIT 3,
Poorly preserved specimens comparable to olsson *s
species occur in the uppermost type Progreso formation.
They have stronger concentric
folds and coarser radial
sculpture than those shown in olsson' s figures of C*
spieker! from Peru. Olsson (op. cit., p, 118) mentions
the occurrence of C.
spieker! In Scuador. In Peru, the
species occurs in the Dpper zorrltos formation (Lower
Miocene).
Material: 3 specimens from locality I.P.C. 500,
south of Progreso,
Chione {Chionopsis) dauleana Marks, sp. Nov.
(Plate 3, figs. 5, 8)
Description (based on holotype and 8 paratypes):
shell large, elongate, tumid, Intricately sculptured and
concentrically frilled.
Height/length ratio
J?%
to 80^,
Anterior ventral margin rounded; posterior pointed; posterior area flattened, sculptured with radials finer than
on rest of shell, Umbonas smoothly rounded, generally
worn to show only faint radial and concentric lines (one
'-■
120
uneroded specimen ie frilled even on umbones).
Lunule
large, cordate, slightly sunken, sculptured with concen-
tric wrinkles, defined by impressed line, equal in both
valves.
Escutcheon narrow, elongate, impressed, with
prominent nymphs protruding to level of escutcheons! margin.
Posterior-dorsal slope narrow, flat, sculptured only
by concentric wrinkles (and frills on well-preserved specimen).
Radial sculpture fairly regular, coarsest on canter
of valve, finest on posterior and anterior areas, obsolescent on ventral margin of shell.
Concentric sculpture
of frills that attain at least two mm, altitude, but are
ordinarily worn down to level of shell surface, most
closely spaced on ventral one- sixth of shell. Hinge not
known.
Variations prominent in
degree of erosion of
outer
surface of shell, resulting in removal of concentric frills
and varying relief of radial sculpture.
Dimensions of holo-
type (both valves): length, 74.0 mm* ; height, 36,8 mm* ;
convexity, 43.7 mm.
Slight paratypes arc of similar size
and proportions.
The Heosnt species most similar to C. dauleana is
£*
(Chionopsis) gnidia of the west coast of Mexico.
fflildla
C.
,
is much higher and coarser sculptured than C*
dauleana; however, the eseutefteonal, lunular and marginal
features, as well as the genera! appearance, are the same
in both species.
The Miocene species closest to C*
121
dauleana is c* (Chlohopsla) spieksrl Olsson of Peru, which
is higher
and has a
straightor postar.ior-4orsal margin,
The new species occurs near the base of the nßlue
siltstone" member of the Daule forma.tion, Middle Miocene.
A single, imperfectly preserved specimen was found as
float near the base of the Progreso formation in the subi-
baja sector of the Progreso Basin (locality 7300-a),
This
is one of the few species common to both the Pauls Basin
&nd
Progreso
Basin Miocene strata.
Material: holotype no. 20438, Paleontologies! Besasrch Institution, from locality 1.P.0. 1082, near village
of Pedro Oarbo, Oaula Basin, Sounder.
(five specimens) from locality
I,P.C.
Para types
no. 20439
1060, ease district.
Paratypes no, 7979 (two specimens), Stanford Univ. Paleo.
type coll., from locality I.P.C* 1060.
Subgenus Lirophora Conrad , 1863
Type (by original designation) , Venus athlete Conrad
( s V. Ist!l
irate Conrad), Miocene to Recent, Caribbean
sea.
Chione (Liregbora ) aff. C. (L.) latllirata (Conrad)
A single mold of a species related
was found at locality
l.p*c.
of the Zaoaehun section.
7498 in the
The
ity 7764-A, west of Progreso,
sate
to
c. letHirata
Progreso
foriaation
species appears at local-
the ribs of a large specimen
number 11 and have fine radial indentations ventrally. fhln,
122
high flanges apparently
were
present
on the posterior area
adjacent to the escutcheon.
Chione (Llrophora) sp. a.
A single specimen with the anterior one-fourth and
umbo preserved is similar to some variants of C, ( Llrophora )
latllirata Conrad,
mmmmmmmrmmmr******* mmmmm&»mmmm>*
The strongly raised lamellar ribs are
w
five in number, with broad, flat or concave interspaces.
From typical C. latllirata it differs in having a larger
lunula, longer hinge-plate, and thinner, fewer lamellar
ribs.
If complete, the specimen would laaasure approxi-
mately: height, 18mm*; convexity (left valve), not count-
ing ribs, 6.3 mm.
The specimen occurs at locality I.P.C.
877 , Subibaja formation, Lower Miocene of the Las Masas
sector.
Chione (Llrpphora) sp. b.
Molds of large specimens were found at locality 529
in the type
Progreso formation,
Middle Miocene.
The ex-
amples have about eleven heavy, high, rounded ribs with
narrow interspaces, thin on the posterior area.
Radial
indentations occur on the ventral sides of tha ribs.
largest specimen Is 36 mm. long.
species
occurs in the uppermost
A
The
Similar, undescrlbed
type Oatun
formation.
C.
(Llrophora) oolombiana ieisbord, Miocene of Colombia, is
similar, but has only eight ribs.
123
Family Tellinldae
Cenus
Telllna Linne, 1758
Type (by subsequent
designation, Children. 1823),
Telllna radlata Linne, Recent, feet Indies,
Subgenus Eurytelllna Fischer, 1887
Type
(by raonotypy), Telllna punlcea Born, Hecant,
west coast of northern South America.
Telllna (gurytelllna) amenensis Olsson
■m >m*m,-zMiy*mm»Hm»
nm-iutmr.'.
M«*wwL).rmMJK»*.i»» »^*im>*<w**m»**><»mmmm
imm«it>mmmt(MmWit'mutmt!
.'mwmmm
t
Telllna (gurytelllna) amenensis Olsson, 1932, Bull. Amer.
pp. 112^X13, pi. 13, figs. 2, 8.
Numerous topotypes of Olsson' s species were found
at locality 508, south of the town of Progreso, in the
upper part of the Progreso formation, Middle Miocene.
Telllna sp. a.
A rather
small Telllna with closely spaced, over-
lapping lamellar ribs, bald on the umbo, and very weakly
sculptured before the posterior angulation, occurs In the
Zacachun section, ranging through the upper 390 feet of
the zacachun member of the Subibaja formation, Lower Mio-
cene. Specimens were found in cores from the zacachun
corehole at depths 68-71, 180-130, 140-150, and 450-459
feet.
The largest specimen is 24.0 mm, long by 15.5 mm.
tall. The species is closely related to T. alternate,
Hecent, west coast of the Americas.
124
[email protected]
sp. b.
A medium sized species of Telllna
with fine,
lamellar ribs present on the central portion of the shell,
but smooth elsewhere, occurs in the zacachun member of the
Subibaja formation.
Specimens were found in cores from
the Zacachun corehole at depths of 80-90 and 250-260 feet.
The largest specimen measures 32*5 x 19.6 am.
is related to
T,
simians, Recent, west coast of the
Americas.
Type (by monotypy)
, "Telllna meyerl Phil." (" Tel-
«,. «. am,*,,
(Metis, fi. and
—.
Applymetis Salisbury, 1929
Genus
_,
The species
« »,^
a. Adams, 1856; not Metis Phllippi, 1843).
)
apolymetls trinitaria colomblensls(??eisbord
mmm
wm\fc\wimmm<'m*'mm*mi'«my,tmmmmm*
m«»mmmmummvm*>^tm^m*m
in.*,
.fr.ri.im*. n*
mmm* wn»*»., mm<Mmmiimmtivm v»a 'iww.ni
Metis trinitaria Colombians!s felsbord, 1929, Bull. Amer.
Paleo., vol.' H7TFr~2&6~iS7, pi. 5, fig, 6.
'
As noted by
isisbord, this subspecies is somewhat
less elongate anteriorly than A* trinitaria (Ball) from the
Trinidad Miocene.
the
In Ecuador it occurs near the top of
*£aaai calcareous" member
of the Baule formation, in
strata believed to be of early Middle Miocene age,
Material; several specimens from locality I.P.C.
1174, Rio
Ecuador.
pauchal
sector of the Daule Basin, southwestern
125
Family Isfactridae
Genus Mactra Linne,* 1767
m*mm»mmmi » hwwwmw
Type (by subsequent designation, Gray, 1847), Maetra
(* Cardlum
' w Recent, seas
*
Linne),
stultorum (Linne)
stultorum
v
m
wrnmum
mwmmmi*
of
■*
,iii.niiin.l
.»Mli i1iii*l
i.*iWii
Mimm*wty*m>mm:.<
mmmm
m.mmmm»mmm*>mtm hi
Europe,
Subgenus Maetrotoma Ball, 1898
Type
(by
"»*'«'
...
original designation), Baetra fraglila
.i„,i..T«ti
w
pp^»
t
i.».p»,..p.....jii
iiiiii
vi
ii.ii
i
Cmelia, Hecent, '"insulss Micobarlcas*1 (Gmelin, p. 3261),
actually yest Indies.
Maetrs (Mactrotoma) irldia Olsson
baetra (Maotrotoma) irldia Olsson, 1932, Bull. Amer. Paleo.
voITTIF, n0."68, p,~T28 s pi, 14, fig. 5.
M*
,
l^idia was described by Olsson from specimens
collected In railroad cuts between Amen (now Progreso) and
Playas.
The cuts are In the Progreso formation, here called
Middle Miocene*
as noted by olsson, M. irldia is closely
allied to M. californlca Conrad,
A
small specimen from
locality I,P.C. 11202, Subibaja foriaation, Lower Miocene,
shows that the hinge is virtually identical with that of
the living west coast M. californlca.
The Miocene species,
as noted by Olsson, differs from the Hecant species by being higher and larger.
The shell material of M. iridia is
somewhat thicker than that of M. californlca.
The sole occurrence of v* irldia in the Lower Miocene
strata of Ecuador is at locality I.P.C. 11202, Subibaja
126
formation, Las Masas sector.
The species is rather common
in the Middle Miocene Progreso formation, from which all
the remaining specimens were collected.
Material: one specimen from locality I.P.C. 11202,
several specimens from localities I.P.C. 7618 (base of Progreso formation) and 508 (type Progreso formation).
G6nus Mac trinula Gray, 1853
Mac trinula Gray, 1853, Ann. Mag. Bat. Hist,, ser. 8, vol.
""11, p. 41. Type (by monotypy) , "M. plicai»ia ff (g Mactra
plicatarla LinnC).
Mactrella
Gray, 1853, op. cit., p.
HTliTriatula
41. Type (by monotypy),
( s Mactra striatula Linne).
No examples of Mac tr inula were noted in the icuado-
rean Miocene strata.
Genus Mactrellona Marks, gen. Nov.
mmimm*mmmv.iiim<m<imm*>mmmiiii:zi-'
Mactrella of authors,
mmm*
not Gray, 1853.
Genotype (here designated), Mactra alata Spongier,
Recent, West Indies.
Mactrellona is proposed in order to provide a name
for the group of mactroids that includes "Jyfaetra" alata
Spengler, "Mactra" cllsla Ball, and "Mactra" exoleta Gray.
This group has been called Mactrella by many authors, who
have mistakenly regarded "Mactra" aiata Spengler as the
genotype.
Gray*s
diagnosis of Mactrella actually fits
"Mactra" alata rather than "M_." striatula: but, according
to the International Rules of Zoological Nomenclature,
127
"M. w strlatula must be considered the genotype of Mactrella, which thus becomes a synonym of Mac trinula.
description
1
Gray's
of Mactrella is as follows:
Ann. Mag. Nat. Hist., ser. 8, vol. 11, p, 41 (1853).
"4. Mactrella. Mactra B and B, Gray, Mag.
N. 8.~TT3H7 Shell cordate, triangular,
thin; hinder lateral tooth very short, rudi- "
mentary, and near the cardinal. M. strlatula.
This diagnosis fits M. alata Spengler, but not M.
strlatula Linne, which is of normal thickness and has an
elongate posterior lateral tooth.
Furthermore, in the
2
"Mactra B" of his prior paper, Gray includes In the synon2
A synoptical catalogue of the species of certain tribes
or genera of shells contained in the collection of the
British Museum and the author's cabinet; with descriptions of the new species," Mag. Nat. Hist., n. ser.,
vol. I, 1837, p. 372.
n
ymy of "M. striatula , tf»
carinata Lam. (= M. alata spengler,
fide Dall, 1894, p. 26, and Lamy, 1917, p. 264).
In view of the evidence cited above, it appears
that Gray based his concept of Mactrella on specimens that
did not include the true Mactra strlatula
Linn^.
Opinion 65 of the Rules of Zoological Nomenclature
states
"If an author designates a certain species
as genotype, it is to be assumed that his determination of the species is correct; if a
128
case presents itself in which it appears that
an author has based his genus upon certain
definite specimens rather than upon a species,
it would be well to submit the case, with full
details, to the Commission..."
One interpretation of this opinion indicates that Mactra
strlatula
Linn!'
Gray, unless
should be considered the type of Mactrella
proof can be established that Gray based his
concept of Mactrella on certain definite specimens of an-
other species (presumably Mactra alata Spengler).
1
Ing to information furnished by I. R* Cox
mmmmmmmm
Accord
-
of the British
mmmm
1
Personal communication, December 7, 1948.
Museum (Natural History), where Gray's material is stored,
It is not possible to show definitely what specimens Gray
had In mind when he cited M. striatula as the type of
Mactrella. Furthermore,
Dr,
Cox states that,
"...there are two specimens among our older
material stuck on a tablet labelled M. strlatula; these may well have been seen by Gray,
ancTthey belong to the species figured by
Reeve (Conch. Icon., Mactra, Pi. 111, Sp. 12)
as Mactra striatella Lamarck.
...
Isuggest, therefore, that Mactrella Gray
was founded on specimens of M. striatiTla
slip" of "the pen,
Lamarck which, presumably by~a "
had been labelled M. strlatula.
by
striatella
Lamarck is the genotype
Since Mactra
mmmm
mcmmmmmm
..—.igin.wii.l
''I mm*
*rt»r.—wMiiiii.i
i.i«.m.i.awMi
w
original designation of Lepto splsula Ball, 1895, and Leptosplsula is considered to be a subgenus of Spisula, the position of Mactrella is not greatly clarified.
129
<
"Mactra" strlatula Linne* and toctra n plicatarla
Linne"' are congeneric.
The two
species
are morphologically-
nearly identical, both being of moderate size and thick-
ness, with concentric undulations and possessing an elongate posterior lateral tooth as an element of the hinge.
Both are living in the Indo-Pacific region,
M. plicatarla
(erroneously recorded by oray in 1853 as M* glioarla) is
the genotype of Maotrlnula Gray, and Mactrella Gray must
be placed In the synonymy of Mac trlnula,
It seems best to dispose of Mactrella
Gray
manner, since no definite and
in this
evidence is
available as to what actual specimens Gray had as the basis
for his concept of Mactrella.
Ifce Mactrella of authors,
typified by wMaotra w alata Spengler, may thus be known by
the new name Madtrellona,
Maetrellona cf*
M,
exo.leta (Gray)
A single poorly preserved specimen from the basal
Progreso
formation south of Zaesehdn is similar in shape
and hinge structure to the Hecent west coast M, exoleta.
It differs from the Recent species in being smaller and
thicker-shelled. Dimensions of specimen (both valves,
with posterior missing): height 47 mm,, distance from beak
to projection of anterior extremity (measured in horizontal
plane) * 21 mm.
.-,
130
Ganus Anatlna Schumacher, 1817
tm
Type (by monotypy), Anatina pellucida Schumacher
il* ty
Mactra anatlna ypanglsr), Recent, ?Paoific coast of
ssjk**
:
.
Mcxico
subgenus fiaita Gray, 1853.
Type (by monotypy),
g.
campechenals (Gray) (Lutra-
ria canaliculate say) , Recent,
Anatlna (Ra§ ta )
undulata
Indies.
(Gould)
(Plate 5, fig. 3)
Lutrarl a undulata Gould, 1851, Proc. Boston Boo* Nat, Hist.,
"~voT7 4\ p. 89. (Recent, west coast of Mexico.)
Olsson, 1932 and Grant and Gale, 1931 give adequate
synonymies of this species,
Olsson (1932, Bull.
Azner,
Paleo. , vol. 19, pp. 131-133) states that true A. undulata
is found only in strata of Late Mioses* age (Tumbez formation) or younger in Peru, and that the smaller subspecies
1* pndulata gardnerae Spieker occurs in Middle and Lower
Miocene strata.
The souadorean specimens are indistin-
guishable from true A. undulata of the Recent fauna.
Hie
largest specimen is 69 mm. tall— as large as the average
full-grown A. undulata living today.
In Ecuador, A. undulata occurs In the Middle Mlo
cene Progreso formation.
thus be
The range of the species must
extended to the Middle Miocene.
Material: hypo type no. 20440, Paleontological Re
search Institution, from locality I.P.C. 508, near the
131
village of irogreso.
Three additional specimens from
the same locality.
family Saxicevldae
Oenus Fsnope Menard, 1807
Type (by subsequent designation, children, 1823),
y\:j.Ty
Pa.nope aldrovandl Menard {«
Ifya glycimerls
Born), Mediter-
ranean Sea.
Panope
cf,
P. cequimbonsis (d'Orbigny)
Plate 6, fig. 10)
Pa.nopea cf ,
Amer*
cofrulmbenala d'Orbigny, Olsson, 1932, Bull.
PaTeo* , vol. 19, p. 145, pi, 13, fig. 6,
Description of the leuadorean specimens (based on
hypotype and six additional specimens); shell large, elon-
gate, gaping broadly posteriorly and sli#*tly anteriorly,
Sculpture of low, irregular concentric folds and fine
lines, with numerous distinct, rounded folds on the urnbones.
Cardinal araa with a distinct furrow extending
posteriorly from a point above the posterior end of the
nymph.
Right valve hinge with a strong ..nymph, a moder-
ately deep resilium pit, a strong anterior tooth, and a
lateral ridge extending anteriorly below the dorsal margin.
Dimensions of figured specimen (a right valve): length
(nearly complete), 101 mm.; height, 63 mm.; convexity,
ZZ mm.
This appears to be oonspeclfic with P. co%uimbensls,
132
but both d*orbigny*s and Philippics figures of the original are too poor for certain identification, Phllippi f s
description tallies with the present specimens, and his
figure (1887, pi. 34, fig, 1) indicates the posterior
cardinal furrow and
strong anterior tooth that
ent on the Ecuador can specimens.
are pres
P. generoaa (Gould.,),
Recent, west coast of North America, differs from the
present
species by being higher posteriorly, lacking the
posterior furrow on the area and the anterior ridge below
the dorsal margin, and having a very small anterior tooth.
Panqpa eoquimbenals (d fOrblgny) was described from
specimens obtained in the Coquimbo beds, Pliocene? of
The material from Peru was found in the Cardalitos,
Chile.
Middle Miocene, and Tumbefc, Upper Miocene, formations. In
Ecuador the species is quite common in beds of the upper
Progreso
formation, Middle Miocene, and rare in the Daule
formation of the Daule Basin.
Recent species of Panope are confined to temperate
and cold seas.
Ball records ?, generoaa Gould ver. glo-
bose Doll (1896, Trans, tfagner ,Free Inst*, vol. 3, p. 831)
from the head of the Gulf of California, which is de
cidedly a warm temperate or sub-tropical locale; but this
occurrence has
not been
verified by later extensive col-
lecting.
Material:
hypo type
no. £0441, Paleontologieal
133
Research Institution, from locality I.P.C. 5275-A, western
Daule Basin. Additional material from localities 529, 508,
and 534 of the Progreso sector of the Progreso Basin.
134
Class SCAFHOPODA
Order SOLKNOCONCHA
Family Siphonodentallldae
Genus Cadulus Phllippi, 1844
Typs (by subsequent designation, Herrmannsen, 1846),
Cadulus ovulum Phllippi, fide Pilsbry and Sharp, 1897,
subgenus Gadlla Gray, 1847
Type (by original designation), Dentallum gadus
Montagu, Recent,
Channel.
Cadulus (dadlla) sp.
Shell small, moderately slender, curved, the dorsal
side convex, the ventral side concave, tapering from the
center of the shell toward the posterior, swollen from the
center of the shell toward the anterior, with a slightly
■ate pronounced swelling just behind the anterior end.
The
anterior swelling Is most prominent on the dorsal side and
barely perceptible on the ventral,
surface smooth except
for inconspicuous growth lines at an angle of about
65°
to
the axis of the shell as viewed from the side; apical open-
ing small, unslit; shell material opaque.
Dimensions;
length, 8.0 mm.; greatest diameter, 1.2 ma.; diameter of
anterior opening, 0.6 mm* ; of apical opening, o*3 ma.
This species somewhat resembles C. panamensla Pilsbry
and Sharp, but has a more pronounced anterior swelling and
lacks the transverse lines near the apex.
It occurs In the
135
uppermost strata of the Subibaja formation, Lower Miocene,
Material? one specimen fro®
the Zacaohua corehole,
depth 80-90 feet, Progreso Basin, Ecuador.
136
Class GASTROPODA
Subclass STREPTONTSDRA
Superorder AB?!DOBRANCH!A
Orddr RHIPIDOGLOSSA
Family Trochidae
Genus Calliostoma Swainson, 1840
Type (by subsequent designation, Herrmannaen, 1846),
Troohus conulus Linne",* Recent,* Mediterranean,
mmmmwm*miwmmmtmmmttnm
mmmmmmtmim.*mimmmmmm
Calliostoma grabaui Maury
Calllostoma grabaul Maury, 1917, Bull, irner. Paleo.
, vol.
5, pp. 155-156, pi. 24, fig, 19*
A single example of
this ornate species was found
at locality I.P.C* 1227 In the Saule formation, Middle
Miocene of Ecuador.
The same species was noted in the col-
lection of T. F. Thompson from the Gatun formation of Panama.
Family Vitrinellidae
Oenus
Teinostoma H. and a. Adams, 1838
Type (by subsequent designation, Cossmann, 1888, p.
**) » Teinostoma pollturn A. Adams, Recent, scuador.
Teinostoma sp. a
Two specimens of an undescribed species were found
in the uppermost strata of the Subibaja formation, Lower
Miocene,
The shell Is 3*3 mm. in diameter.
It resembles
T. ecuadorianum Pilsbry and Olsson (A. N. S. P. Proa., vol.
137
93, (1941), p, 47, pi, 9, fig, 1) and T. depressum Gabb
(op. cit., vol. 73,(1922), p. 398, pi* 37, fig, 2), but
differs from them by being more depressed in shape.
Material: two specimens from the Zacachun corehole,
depth 80-90 feet, progress
Basin.
Teinostoma sp. b
Two poorly preserved specimens were found in the
medial strata of the subibaja formation, Lower Miocene.
The larger is 2 mm. in diameter.
The specimens are more
inflated than the T* from the uppermost subibaja formation,
but less so than T* depreeaa (Gabb) of the Santo Domongo
Miocene.
Traces of spiral lines are evident on the periph-
ery of early whorls.
SSaterlal: from corehole Bos Bocas no, 1, depth 70-80
feet,
zacachun sector,
Progreso Basin, southwestern
Ecuador.
138
Superorder CTKNOBRAN'CHIATA
Order PLATY.FODA
Suborder PT3NQGLO3SA
Family Archl
tec ton!cidae
Genus
Architectonica adding, 1798
Type (by subsequent designation, Gray,
1847),
Trochus per spec
tlvus Linne,* Recent, Indo-Facific.
miWmMmmmmmmmmmmmmm
i*iiiWi*Mi<i>*«w>iwww»iiiHi*i<iwni*
m>tmmm<amm
Arohi tec t onl.ca nobllis Rdding
tec tonloa nobilis
~~ nodlag, 1798, mus, Eoltenianum,
Arch
" i
pi."*." p. 70,
,
Solarium granulatum Lamarck, 1016, -3ncy. ieth. p. 10,
pT, 44&, ?Tgs. 5 a-b (not seen by writer).
(The following references include only the citations of
tropical .American Miocene records* )
Solarium yillarelloi Bdse, 1906, 801. Inst, Geol. Mexico,
no. 22, p. &©, pi* 3, figs. 4-11 (also fide Olsson,
1922, p. 154; but not i.e. ioodring, 191H7"p. 355),
Solarium gatunense Toula, 1909, Jahr. Kaiser. -Kan, Ceol.
RefchsanstaTl vol. 58, p, 692, pi. 25, fig. 3 (2
figs, ) ; not Solarium granulatum gatunansis Toula,
Brown and Pll¥Bry7nL*9ll7^7^oc » Acad. Hat,'"'"sci, Fh'lla*
vol. 63, p. 360 {?
Architectonica sexllnearis
lsir y '""THT, op7cit. "," vol. "83,
cprusca Olsson); Pl
p, 432*
,
,
"
}
1917, Bull, Amer. Paleo.
granulatum Lamarck, Maury,
Solarium
,
i^_r
■afeMi.w*v*+wr^«*#*mm^i^*^»m*
m
m ■
If;
p.
pi.
fig.
3,
131,
23,
voTT ITno.
..ii,i
*-h*II
i
I
i„i*!Wl|i
imni.ggWWWli
M
_*
_^
>i
,
Architectonica granulate (Lamarck), Olsson, 1921, Bull. Amer.
Faleo. , voir*!," no. 39, p. 154, pi. 13, figs. 10-12;
Maury, 1925, Bull. Amer* Paleo., vol. 10, no. 42, p. 236,
pi. 40, fig. 1; Hodson, F, and H. X* , 1927, Bull, jyser*
Paleo., vol. 13, no, 49, p. 66, pi. 36, fig, 7; Anderson,
F. M* , 1929, Pros. California Acad, sci,, vol. 18, no, 4,
p. 122; oinomikado. 1939, Jour. Geol. Soc. Japan, vol.
46, no. 555, p. 620, pi. 29, fig. 11,
139
Architectonica gatunsnsls Toula, Anderson, 1927, Proc.
vol, 16, no, 3, p. 89 (list).
California
anuletum (Lamarck), felsbord, 1929, Bull,
, no. 54, pi. 9, fig* 15,
Architectonica
3r* Pa
Boding
*** cited
a.
mm
A. no-bills.* '
perspeetiva,
* mm
A. gothica,"
t mm
.rfP|».-».
A.p».
ip»i.i..u>»iipp».iiip
,1.,,,n,
«ilp»».i.ipp
mi
WmwWmwmmMp.
hpiphh.
78-79 of the Museum Boltenlanum. For
"*"
a. radiata on pp*
an indication of a. nobllls," he gives "Qael, T. perspectlvus,
and
mmm
■
.niinfttiWinWiiiuliniiiwmiMM,mm
pm
mihi.ii
.pi
num
*"*
mm
*t<— Ußimil.iiiiiirtSnnnMl■,»»■,■
p»h
iliimnn
sp. 3, sohr saltan, Ghemn. 5, t. 172, f. 1695, 1696." Gmslia
(1792, pp. 3566-3567) lists a number of references to figures
under his "Trochus" perspectlvus, including "Chcmn. Conch 5,
p. 3, vign* 42, f. I, t. 172, f. 1691-1696."
Chemnitz's
figures, 1695 and 1696, plate 172, appear to be the Recent
Caribbean mM fast Coast species, while his other figures
■
are markedly different. Furthermore, Chemnitz (1781, Neves
Syst. Conchi lien-Cabinet, vol* 5, p* 126) states that his
figures 1695 and 1696 are from the Spengler collection;
and the majority of Spongier *s collection was made in the
.Danish iest Indies, Greenland and Guinea (fast Africa),
Thus It is probable that the specimen figured by Chemnitz
is a lest Indian shell. Solarium granuleturn Lamarck,* 1816
tiMWMiiiiM'«i^M*MM»*i^iMiiM*n
■
mwSmmmmtmmmmm*^nm
t .wm.timk^mum
(for which no locality is cited) must therefor®
1
mlzed with the prior a. nobilis.
1
be synony-
The writer Is grateful to Dr* Leo- G. Hartlein for suggesthe nomenclature of A. nobllls.
tions about ,
. ..
mmm.mmmm** mummmmm m* m m*.■» m
i*
W 'fit
A. nobills is the common living species of the
Americas, with range on the West Coast from Lower California
140
to Peru, and on the East Coast from North Carolina to
Trinidad,
Recent.
The stratigraphic range is Lower Miocene to
Comparison of about thirty Ecuadorean Miocene
specimens with Recent specimens shows that all the Ecuador can fossils are within the range of variation of the
species.
Ten virtual topotypes of "Solarium gatunenee
Toula" from the Gatun formation of Panama cannot be disof Recant A. m.mmwnm
nobllls.
tinguished from a similar assemblage
mm
fun
iiiiii ill
Olsson (1922, p. 326) -and others also have placed a. gatunense in synonymy with
A.,
nobilia. The most useful charac-
ter for identification of the species is the narrow periphoral band with a beaded spiral thread lying in the sulci
above and below,
In Ecuador,t mm
A. nobllls occurs in the Lower Miocene
imwMirMn iub.i-jihl.ic.
Subibaja formation of the Las Masas sector, and In the
Middle Miocene Baule formation of the Baule Basin.
It is
also present In the basal Miocene Angostura formation of
northern Scuador.
Material; specimens from localities 2558, 11203,
and 11205(?) of the Las Masas sector, northeastern Progreso
Basin, and from localities 1. P. C. 1437, 1457, and 1464
of the Jerusalem sector, Baule Basin.
141
—
Architectonica aff. A. nobllls adding
wiMIPWIi
i|ii.W.iii.llii>|p*W.p.i.
HliMWl—
*W«.*lliiWirtl»
iH|!W»lW*>liiPilllW«ilWl"l
(Plate 7, fig. 3)
Specimens from the Lower Miocene strata of the Las
Mesas sector have tha sculpture peculiar to A. nobills except that the last half-volution of the spire is but feebly
granulated
,
the central four spiral bands of the base are
barely Indicated by Impressed lines with no granulations
present*
Radiating impressed growth-line traces are promi-
nent on the base, and the fine spiral thread that lies above
*
the peripheral
cord on typical mmA. nobille
is not present.
,
*
*"*■
.I,
ipuniii.p
,v ».,
ppip
».p.
■*"
The two best specimens measure 16.7 mm. and 16,4 mm* in
—
diameter, both nearly complete and apparently mature.
*?
The specimens thus distinguished are known to occur
only in the Subibaja formation of the Las Masas and Carrizal
sectors of the Progreso Basin In the strata of isarly Miocene
age *
Materials hypo type
no,
20442, Paleontologlcal Research
Institution, from locality I. P. 0. 11200, near the village
of Las Haass*
Additional
specimens from localities I* P. C.
11200, 11204, and 877(?) of the Las Mesas sector, and locality
I.P.C. 11091(f) of the Carrlaal sector.
142
Architectonica sexllnearls subsp.
**' eorusea Olsson
.w«WMiw^..'M.»iWii'MH<w*M^
M-Mw-mmmimmmimmmzvi
»z-*mz/*m*! -iMiii timmmmm
m*
zm^mtmrnimmmmmmit
Architectonics sexllnearls eorusea olsson, 1932, Bull, Amer,
~T>aieo.r^!TT^TaS7TB, pTTI4, pi. 81, figs, 5, 8, 9.
The holotype of the subspecies is from the Miocene
of Costa Bios, other material is from the Lower Zorritos
formation (Lower Miocene) of Peru (Olsson, loc. cit.).
as noted by olsson, a. sexllnearls eorusea differs
from typical A. sex!i
nearis in having the spire whorls and
baa©
completely granulated.
Only
&* can- sea occurs In
Loaer Hiocene deposits of Ecuador*
the
The type of A. eorusea
Is from the Miocene of Costa Rica. A large collection from
the Gatun formation of Panama, sent to Stanford University
by T. F. Thompson, contains specimens of A.
eorusea . from
several localities, including the true basal strata as distinguished by Thompson.
Specimens from locality I.P.C. 529, Progreso forma-
tion. Middle Miocene, are apparently intermediate forms.
The later spire whorls are but feebly granulated, the body
whorl lacks granula tions, and a thin spiral thread lies
just above the peripheral spiral,
ftie base ia not known.
The same variety occurs at locality 1227 in the Baule Basin.
souador,
*"*
In
w
P
A,
mm
■
sexllnearls eorusea occurs In the
null
■
HIHHM
iwiiiUppipliiipihi nil,
Hilllu
il
uppermost strata of the Subibaja formation, Lower Miocene,
in the Daule formation, Middle Miocene, and. in the basal
Miocene beds of the
Angostura
formation of northern Ecuador.
143
haughti Marks, subsp.
***
**
Architectonica sexlinearis subsp,
nov
>i*Wti.^li^,Mii*.*Miin.iiiiii.iiin,
.iniir*
|(pi.i
W(
>'iiiirtiin.l|iii.i l
i.»
ai,\mmimnmmmmmm*im\
P**»i«w***.3«i*.ii'.i-;r.i*»iw
iimnimm ■.m*m
■
(Plate 6, figs, 2, 6)
This subspecies, represented by two specimens from
the Baule Basin, Middle Miocene, differs from typical A.
aexlinasris in having the central two spiral bands of the
spire whorls united, and in having a somewhat narrower
peripheral cord,
The nucleus and first two spire whorls
The last two
are identical with those of a. sexllnearls.
* mm
mmm*
.itmm»m«\mmmm«'
r*w <» ****+***, mi hwi
spire whorls and the base are barren of granulations.
Dimensions of the holotype; length, 12.5 ma,; diameter,
20.0 mm*
Dimensions of paratype (not figured): length,
23.6 im*i diameter, 35.7 mm* (last quarter-whorl missing).
No stratlgraphic significance is attached, to- this
subspecies.
Its biostratigraphic value may be shown by
future records In other places.
It occurs In the nßlue
siltstone" member of the Daule formation, Middle Miocene.
Associated with it are A. eorusea Olsson, Katica gappyana
Toula, etc.
The name haughtl is given for 0. L* Haught,
who mapped most of the Daule Basin.
Material: holotype no. 20443, Paleonto logical Research Institution, from locality 1464, near the village
of Jerusalem, Daule Basin, Ecuador.
Paratype no* 20444
from locality 1227, nine kilometers NNf of the village of
Pajan, Daule Basin.
144
Suborder TahNIOCHjOSSA
Family Calyptraeidae
Genus Cruclbulum
Schumacher, 1817
Type (by original designation), Cruclbulum
rugpac-
coststurn Schumacher plus C. planum Schumacher (* patella
auricula Gmelln, fide Billwyn, 1817, p. 1017).
Subgenus Cruclbulum
s.s.
Cruc ibulum (Crucibulum) ecuadorense olsson
Cruclbulum (Cruclbulum) gcuadoreuse Olsson, 1932, Bull.
amer. Paleo. vol. 19", p. 2l&7''pl. 24, fig. 11*
,
l
Seven topotypes of the species were collected at
locality I,P.C* 508 in the upper part of the Progreso for-
mation, Middle Miocene of Ecuador*
Family Natleidae
o®&t*«
Natlea Scopoll, 1777
Type (by subsequent designation, Harris, 1897),
ta vltellus Linne, Recent, Indo-Pacifie,
NcrI
The type species has a very low, barely distinguishable funicle; the umbilicus is sealed on dts top (posterior)
side by polished callus and, as noted by Marwick (1924), the
plane of the outer lip inclines at about 25 degrees to the
vertical axis of the shell.
The outline of the spire, seen
from the side, is rather subquadrate.
The nucleus consists
of two rapidly expanding whorls with a moderately small,
low apex.
Subgenus Natlea , s.s.
145
Nat lea (Najica) sp.
(Plate 6, figs, 7-9)
Description (based
on 9 specimens); shell of low
spire and moderate size, globose, but with subquadrate outline of spire.
Nucleus of about two barren whorls, the
Spire of about 3| whorls of regularly
apical one small.
increasing size.
length,
Body whorl about 80 per cent of total
sculpture of rare, fine growth-line traces.
lines marked by brown color-bands.
Growth-
Sutures abutting. Aperture
sub-ovate ;parietal wall calloused, the callus extending over
tha*st«
the upper part of the umbilicus; plane of outer lip at angle
of 35 degrees to vertical axis of shell (on one specimen with
outer lip complete),
Ombllicus open, upper part shielded by
callus, with funlcle barely discernible.
specimen ,( es tiaated complete), 23 mm.
no. 20445, length
13,6 mm,,
Diameter of largest
Dimensions of hypotype
diameter 12.8 mm*
This species is nearly identical with N. vitelle (linne ),
type of the genus.
Characters common to both species are;
(1) low spire; (2) subquadrate profile of the spire as viewed
from the side; (3) parietal callus that overlaps onto the
umbilicus; (4) obscure funicle; (5) lack of definite sculpture.
The two species differ as follows: the outer lip of
!" vitalla
inclines at an angle of "20 to 30 degrees,"
whereas that of the Subibaja species inclines at nearly 35
degrees; N. vitella has broad, irregular color markings with
146
an anterior row of whit® spots, whereas the subibaja specias
has fine color bands and no spots; the nucleus of N. yltella
has a large apex, while that of the Subibaja species begins
with a minute whorl. No specimens of intermediate age and
appearance are known to the writer. K. (Natlea) castren-
oides of the Bowdea Miocene is similar to the subibaja
species, differing from it only In Its greater diameter,
better defined sculpture, and large nuclear apex.
(Natlea) sp*
Matlea
occurs In the Lower liocene
Subibaja formation of the Las Masai sector, northeastern
Progreso Basin.
It is found associated with Conus masas-
easis, C. rolgl, Meigasureula guayasenals, etc.
The en-
closing strata are slltstoss and sllty sandstone.
The
species was not named , because no complete, mature individ-
ual was obtained,, no opereula were present, and because of
the possibility that such a simple form may be elsewhere
described in the literature.
Materials hypotype no. 20446, Paleontologies! fiesearch Institution, from locality I,P.C* 11203, near the
village of Las Masaa*
I,
P.C.
Hypotype no. 20445, from locality
2558, same sector.
Additional specimens from
localities 2550, 11303, and 11205.
Subgenus llatlcarlus Burner11, 1806
Type (by
Caribbean
sea.
monotypy), Berlta canrena Llnnrf', Becent,
147
The group of Natlca canrena is distinguished prin-
cipally by the deeply impressed regularly spaced axial
wrinkles adjacent to the suture, heavy funiele, strongly
ribbed operculum and large size.
The outer lip of g»
canrena lies in a plane Inclined at about 20 to 30 degrees
from vertical, larger individuals being the less inclined.
How such weight should be given to opercular characters in
subdividing the genus Natlca is a knotty problem*
For ex-
&apie f Natlca unifasclata Lam. of the West Coast of America
has deeply indented, tangential growth striations extend-
ing down from the suture and a prominent funiele, in these
"
respects
|v%**_
resembling N. canrena*
It has a tightly coiled
nucleus with a tiny initial whorl, and an operculum with
.
a single marginal rib, thus differing from mm.
N
canrena.
mm
The
small protoconch, however, is similar to that of N. canrena
of the Bowden Miocene,
ribbed
* which has a strongly
**"
antlnacca
mum.
m*m#mmml\m*mmm»<m,wn<*
r
i in
operculum.
On the basis of funiele and sculpture, N,
.uni-
fasclata would be classed as a Haticarina; whereas, on the
basis of the operculum, it is classed as a Ma tica s.s,
As noted by foodring, the comparison of all the tropi-
cal American species ascribed to Natlca canrena would be *an
T
exhaustive study." The fact that opercula are rarely preserved as fossils complicates further the proper allocation
of the various forms,
148
Nation cf* H*
mm
lniiiPiilim.,|i.p«i-i.ppiPippii
(Natlcaplus )
—.hpihi,mi'.iiippip»i
in minimJ
■'
canrena antinaaea
iilil.l
pipp
iiili
imipi.i.i.i
p».i»i.
4*
3)
(Plate 6, figs*
Cosemann
'»,p«iiniiiinij»il.l|ii'a»iii.«pl
Nine specimens from the Subibaja formation were ex*
amined*
They are identical in external appearance with
figured specimens
*
of mm
X*
*■"*
canrena antinaaea from Bowden
mimmp«pr,p»p. p.,
....in n
1p,
liii.m pi. .iiuppiup imii
immiwiin
(Woodring, 1928, pi* 30, figs* 6. 7) except for the operculum, which was not found, the else of the shell, and tha inclination of the plane of the outer lipt
mens apparently measure about 08
mm*
the Bowden speci-
in length* while the
Subibaja specimens are no longer than 10.3
The outer
mat*
lips
of several small specimens
of 1.
antinaaea from Bewdea
W
m
m**
ri,p«p».n.im. ipp, ih»,.pp.,ip,p
mump.
incline 10*i4 degrees free* vertical* whereas the same plana
In the present species inclines 40 degrees*
The Subibaja
forms differ from the Hecent I*
canrena in sisa of nucleus.
mm
P
i.«iiiin«-i- iiimiii.iin.iin
site of shell, and inclination of outer lip* Tha apical
nuclear whorl is tlny»~not large and globose like that of
£" ff&nrenat
the Subibaja species resembles 1. livjda Dlllvyn,
Recent,
* West Indies*
m In this respect*
m
■
a tiny nuclear apex*
antinaaea also has
1«
m*
wimiiii.il
,»,i.i,pu ,i....»,,iih.»i
The plane of tha outer lip inclines
at an angle of 40 &egmm from vertical in the Subibaja
species i while tha smallest specimens of I* canrena incline
little more than 30 degrees from vertical*
the largest specimen Clocality I*P*€. £568}t
sir,
j
diameter, Vel lito
dimensions of
length, 10*3
light other speelniens are slightly
sumHer*
Until an operculum is found, the status of the $«&!*
baja species cannot be known*
strikingly similar to 1*
Although the species is
sanr»na»
type of the subgenus
149
Naticarius,
the possibility exists that its operculum may
be that of the Natlca livlda and N. unifasciata group, which
probably -should be placed In the subgenus Na ties s.s. Be-
cause of its general resemblance to and identity of many
specific characters with j£, antlnaoca, the Subibaja species
is herein considered to belong in the Natlca (Naticarius)
canrena group.
Natlcas related to N. canrena are common throughout
the Tertiary sediments of tropical America*
Olsson records
"Natlca near canrena Linne or unifasciata Lamarck" from the
Lower Miocene Lower Zorritos formation of northwestern Peru,
The Lower Zorrltos specimens have a .maximum length of 15 mm.
and may be the same as the Subibaja species,
"N. canrena
Linnaeus" Olsson from the Gatun beds of Panama (Bull. Aiaer.
Paleo., vol, 9, no. 39, p. 327, pi. 13, fig. 9) appears to
have a somewhat more elongate outer lip than Hecent individuals of |U canrena, and in that respect resembles the Subi-
baja forms.
Other records of "Natlca canrena" refer to
specimens from Miocene strata of most of the countries bordering the Caribbean Sea.
.
Natlca cf N. (Naticarius) canrena antlnaoca occurs
in the undivided Lower Miocene subibaja f ormatlon of the
Las Masas sector and in the aubibaja formation of the Zacachun section.
The enclosing strata are siltstone and fine
sllty sandstone.
,
150
Material; hypotype
no. 20447, Faleontological
He-
search institution, from locality I.F.G. 11203, near the
village of Las Masas.
11205.
Five specimens
Two specimens from locality I.P.C.
from, locality
I.'jvC* 2558.
One
specimen from the zacachun corehole, depth 100-110 feet.
Subgenus Stigmaulax Morch, 1852
Type {by subsequent
designation, Harris, 1897),
Natlca sulcata (Born) (« Nor I
ta sulcata 'Born), Becent,
feat Indies.
'
' guppyana
Toula
Natlca
&fe„„l^.PlK*f,l..i.
'»
.. (stigmaulax)
fcfcri..
lIP,
-1..1.P11
ill ,.
lllH.ni-
■,i»,.„„n
Natlca (stigmaulax) guppyana Toula, 1909. Jahrb* der k.k.
geolV" HelcEs. , vol. 58~p. 696, pi. 25, fig. 6;
Olsson, 1922, Bull. Amer. Paleo,, vol, 19, p. 156,
pi* 13, figs. 13-15*
Natlca pguppyana Toula, Brown and Filsbry, 1911, troc. Acad.
Nat7sci. Philadelphia, vol, 63, p. 360; Anderson, 1929,
Proe. California Acad. Sci., vol. 18, p, 123.
Natlca (Naticarius) guppyana Toula, Olnomikado, 1939, Jour.
Geol, Soc. Japan7vol, ""'l6, no. 555, p. 621, pi. 29,
u
X *g. <*.©«
The
geuadoreaa material
was compared with virtual
topotypes from the Gatun formation.
An operculum of the
Gatun specimens bears a central heavy rib, with narrow
ribs before and behind, as mentioned by 'joodring for Stigmaulax s.s.
In icuador the species has been reported from
only the "Blue siItstone" member of the Daule formation,
Middle Miocene.
Material: specimens from localities I.P.C. 1227 (near
Fa jam) , 1457, and
1464
(Jerusalem
sector).
151
Genus Pollnloes Montfort, 1810
Typo (by original designation), Pollnloes albus
Montfort (» Natlca mamraillaris Lamarck
s Hat lea brunnaa Link
Recent, West Indies, fide «jfoodrlng, 1928).
Polinleas coronis (Hanna and Israelsky)
Natlca coronis Hanna and l
eraelsky, 1925, Pros. California
Acad,
sci., ser. 4, vol. 14,
p, 46, pi, 8, fig. 4,
Polinices (Polinlces) coronis Hanna and Israelsky, Olsson,
15417 Bull. 'Amer. Paleo.'7 vol, 19. pp* 207-208, pi*
„„
24, fig. 9.
Numerous specimens were found at locality I.P.C. 508
in the upper part of the
of Ecuador.
Progreso
formation, Middle Miocene
Olsson (op, cit., p. 200) also records P.
coronis from this sector, and from the Variegated beds and
the Montera formation (Middle Miocene) of Peru.
Hanna and
israelsky found It in the Sorritos formation, Lower Miocene.
The Icuadorean occurrence extends the range of the species
from Lower to Middle Miocene.
Family Turriteiliaae
Conus Turritella Lamarok, 1799
Type (by monotypy), Turbo terebra Linne", Hecent,
seas of China (fide Merriam, 1941, p. 26).
Turritella abrupta Spieker
Turritella robusta var, abrupta spieker, 1922, Johns HopTins University, StuaTes In Geology, no. 3. p. S3, pi.
4, fig. 6.
For
further references the reader
may
see olsson,
152
1932, p, 200, and Merriam, 1941, pp. 47-48.
T. abrupta
occurs in Peru in the Upper Zorritos (Lower Miocene) and
Cardalitos (Middle Miocene) formations (Olsson, 1932, p,
201).
Elsewhere In South America it Is a well-known Mio-
cene species.
In Ecuador it occurs in the lower part of
the Progreso formation, Middle Miocene, associated with
,
Meganitaria Clascal * etc.
T* altilira,
,
r muiiWiuftTi'w mmwm
mmm
ii,i«w*p*.iM*iww^iwrß
mmmmmmm*immm\*mm> *m*m<m
wmmmK i>wkt*m< u^mmmmm
Material: specimens from localities I.P.C. 731,
775, etc.
Turritella altilira Conrad
.
1857, Pacific
Turritella
altilira Conrad,
Railroad Reports,
**
*
mmmm.mm
>J *
,
72,
5,
ptT
2" p.
pi.
fig. 19* Brown and Pilsvbl 6
bry, 1911, Pros, Acad. Nat. Sci. Philadelphia, vol. 63,
p. 338, pi* 27, figs* 2, 3, Olsson, 1922, Bull. Aoaer.
Paleo., vol, 9, no. 39, p. 150, pi. "14, figs. 6, 7.
Hodson, 1926, ibid., vol. 11, pi. 26, fig, 1, pi* 28,
fig. 3, pi. 29, fig. 1. Sheppard, 1928, Bull. A.A.P.G. ,
"
vol. 12, p. 671. Anderson, 1929, Proc. California Acad,
Sci., vol* 18, no. 4, p. 118, pi. 17, figs* 4, 5,
Olsson, 1932, Bull, Amer, Paleo*, vol* 19, p. 202, pi.
23, figs* 3, 4 (T, altilira subsp,). Oinomlkado, 1939,
Jour. Oeol. Soc.""japan, vol* 46, no. 555, p. 620, pi.
29, fig. 2. Merriam, 1941, Univ. of California 'Pub.,
Dept. Oeol. sci*, vol. 26, no. 1, pi* 24, figs* 3, 4*
i>.»Mi'ii««NMW.»i.. ■i&wnmmtmM*mmm*
W»Mf*.i mm/iim< jmmmtnimmmmmm
mm
mm
«*
*m.
«.
m*
.*,
T. altilira Is usually found in the Middle ?4locene
strata of South America, although a few Lower Miocene occit., m
p. 46).
'
currences are known (Merriam, op.
m
w
W
_T. altilira
...I..»
mii
ipipp.
""
'-mm
subsp, Olsson Is recorded from the Cardalitos formation,
Middle Miocene, of Peru (Olsson, op, cit., p. 302).
in
Ecuador, numerous examples are present In the Progreso and
jjaule formations,
Middle Miocene, but none are known in the
ittvsoa and
Lower Miocene subibaja formation.
153
Material;
specimens from localities I.P.C. 508 , 529,
531, 532 (Progreso Basin), 1225, 1227 (Baule Basin).
Turritella
cpngulstsdorana Hanna
ana
israelsky
(Plate 6, fig, 13; text figure)
Turritella eon gu1s tadorana Hanna and Israelsky, 1925, Proc,
California' AcafrscfTT ser. 4, vol. 14, no. 2, p, 41,
pi, 7, fig. 5. Olsson, 1931, Bull, tear* Pale©., vol,
17, no. 63, p. 74, pi, IS, figs. 1-3, 5, 7,
T. coa _ulstadorana is the most conmon Turritella in
the Lower Miocene Subibaja formation*
Dozens of specimens
from five localities in the Garrlzsl sector were examined*
None had the protoconch and earliest whorls preserved, so
no new information can be added to the excellent description by Olsson (100. cit,).
Tha growth-line traces are
deeply sinused, with the antisplral maximum well above the
whorl-middle.
degrees,
The growth-line angle varies from 15 to 18
The adult whorl profile is shown In the text
figure.
2*
merriami of the California Eocene and T. con-
Guistadorana have similar mature sculptural and growthline elements, but are not otherwise related,
T. oorey!
Msrriam of the California Upper gocene has a posterior
flange similar to that of T. conguistadorana, but, accord-
a»
_i
ing to Merrlam, its antisplral sinus maximum Is below the
whorl-middle and the
growth- ling
angle is about 10 degrees.
Turritella carrizasnsls Anderson and Martin (Proc, California
154
, ser,
Acad. Sci.
4, vol. 4, 1914, p. 70, pi. 4, fig. 4)
from the Upper Miocene of California also has a posterior
flange, is similar to the Scuadorean species in other
features, and .may be closely related to It.
According to previous work, T, c onc^ulstadorana oc
curs in the Oligocene strata of
Peru,
Olsson (op, cit.,
p. 75) notes;
"The stratigraphic occurrence of oongulstsdoyana in the basal Heath shales of earlyTEaEe
Oligocene age is, .unusual, especially since
no trace of this group has yet been found In
the Late Socene and Sarly Oligocene formations."
.
In addition to being found In the Lower Miocene strata
of Ecuador, T.
consul stadorana
was also noted in the Middle
or Late Oligocene strata of the northern Progreso Basin,
associated with .Ampulllnopsls. fpcnceri Cooke and Anadara
meroensls (Olsson).
l
», J>
i.j,M
.^,i.,ui
J i^.,
l
tni noiiii—
i*
Material: hypotype no. 20448, Paleontologlcal Research Institution from locality 1.P.0. 11092, near Carri-
zal, northern pro&reso Basin*
Additional specimens from
localities 11092, 11093 and 11120.
Turritelle gatunensi a Conrad
(Plate 6, fig. 5)
Turritella gatunenela Conrad, 1857, Pacific 8,1, Reports,
voTTT, p.TFTpI* 5, fig* 20*
Turritella conradl Toula, 1909. Jahr. der k.k. geol. Reicha.
vol. 58 t p. 694, pi* 25, fig. 4.
155
Turritella gatunensis Brown and Pilsbry, 1911, Proc. Acad.
Tifat. loi. Philadelphia, vol, 63, cl. 27, figs. 4, 5, 9.
Olsson, 1922, Bull," Amsr, Paleo., vol. 9, p. 320, pi.
14, figs. 12, 13. Maury, 1925, Ibid., vol. 10, p. 229,
pi. 42, fig, 12. leisbord, 1929, Ibid., vol. 14, p.
265, pi* 9, fig. 7. Anderson, 1929, Proc California
Acad, sol., ser, 4, vol, 18, p. 120.
A single fragment of three early whorls, probably
the seventh to ninth, was found in the
2acachtfn
member of
the Subibaja formation, Lower Miocene, about 200 feet below the base of the Middle Miocene Progreso formation In
the zacachun section.
The three whorls are identical with
corresponding whorls of T. gatunensis from the Canal Zone,
showing the transition from strongly
mesooostate nepionie
whorls to bicarlnate later whorls, and having Identical
minor sculptural elements.
The Subibaja formation is Lower
Miocene, and this is the lowermost known occurrence of T.
gatunensis in southwestern Ecuador,
the species occurs in
the Angostura formation, basal Miocene of northern Ecuador,
but has not been recorded in Peru.
An incomplete specimen
(figured) was found at locality 508, In the Progreso formation south of Progreso,
Material; hypotype
no. E0449, Paleontological
Re-
search Institution, from locality I.P.C. 508 in the type
Progreso
formation south of Progreso. One specimen from
the Zacachun corehole, depth 250-260 feet.
156
Turritella infracarinata Grzybowski
w
*
ptmi
*mmm*m>z*mmvmimmmm-ii->>mmtm
mmm<mmwn*>«t'mMm
■*****..niw.ii' n mw**«n mmtmrnn'm-
(Plate 6, figs, 1, 14)
Turritella suturalis Nelson, 1870, Trans. Connecticut Acad.
Arts and ''&CI- ,'" vol. 2, pt, 1, p* 188, Not (irate loup,
1832, p. 159; not Phillips, 1836, p. 22fT"not Forbes,
1844, p. 189; nof 0. 3. sowerby, 1846, p. tW (fide
Sherborn, 1931, index Aaimalium, p 6337).
Turritella infracarinata Grzybowski, 1899, Neves Jahr. fur
Mln, ," 'oe6l.' v. IPai."',' Bellage-land, vol. 12, p, 643, pi,
20, fig, 5, Spieker, 1922, Johns Hopkins Univ. studies
in Geo!*, no. 3, p* 79, pi. 3, figs, 9, 10. Woods,
1922 (in Bosworth, Geology of Northwest Peru), p. 109,
pi* 18, figs, 2, 3. Stelnmann, 1929, Geologic yon
Peru, p. 200, fig. 247* Olsson, 1932, Bull, Araer.
Paleo., vol. 19, no. 68, p, 196. pi* 22, fig. 8.
J
Turritella rotundata Grzybowski,* 1899,* op. cit., p. 643,
*w<mt>«*.MwmmmmMmwm*i*mmmm*.'
■.<-*,*:,**&>.**,*»*w v.-<■;>
>i*m*w'
pl. 20, fig. m^w*.
6.
v
*m
.
-9
p
m*
(7not Turritella nelson! Spieker var. rotundata
" Spieker,
~T9^2, op. cit.', "p"."' '"97, pl. 3, fig 'V f"i"de olsson
1932).
,
r
.
Spieker, 1922, op. cit., p. 74, pl. 3,
Turritella nelson!
' "
"Tigs "~s", "&" (sa w name for suturalis Nelson).
■
Turritella nelson! Spieker var. trull!asatla Spieker, 1922,
op7crt77^pT7B, pi. 3, fig^Trr"
T. Infracarinata in Peru occurs In the Variegated
beds, the Upper zorrltos (lower Miocene), and the Cardali-
tos (Middle Miocene) formations. In Ecuador it Is common
In the progreso and Daule formations, Middls Miocene*
subspecies (g.v.)
occurs in the Lower lliocene
A
strata, icua-
dorean examples from the Daule Basin era exceptionally well
preserved, and two are figured in this report.
The earliest
whorls are pseudobioostate, the pleural angle is 12-13 degrees, and the angle of the single-sinused growth- line
157
varie* from
30° in young
to 40° in mature individual..
I
laments of sculpture developing after the early bicari-
nate stage attain a maximum number on the largest specimens,
The following table shows the occurrence of spiral
sculptural elements.
Symbols used are thus:
I, ll—
primary spirals; 2— secondary spiral; 3— tertiary spiral.
—
Diameter of whorlSculpture
3
p~p.wnwiuu.il
.ym<imimmn
Iip ■ ,i*mmmmmm
M
]
Iip.iPp.
■■.,..,»,
O
uni piiiiiilßiiimiiwi.i
-14 mm*
,ip.
,,,.
,'.■.
6 wm*
ii
.i
limm.
■TiTnii-
ii i
JL
>*m
mm-
x
x
x
x
A.
jL
7L
mm
"mlk
M*-
Jm
■**
X
X
X
x
x
thread
2
17jmm.
.11.11
XXX
Ik
O
-
33 mm,
n,
x
thread
JL **.
x
thread
-**
&mf
thread
thread
H
I
thread
thread
3
x
x
*
*
X
X
x
x
x
xx
X
X
X
x
-x
&
O
x
XX
«
m
m> *»***.*. m
j.
"■"
||
X
'
-
x
am m.
Occurrence of the spiral elements is more consistent
on the smallsr whorls than on the larger. Considerable
variation takes place in the tertiary spirals and threads
of mature forms. The pattern of the 14-mm, whorl is shown
on the last whorl of hypotype 20451, and of the lj m*m
whorl on the seventh whorl of hypotype 20450 (Plate 6).
Material; hypotypes no. 20450 and 20451, paleonto
logical Research institution, from locality I.P.C. 1465,
158
Blue siltstone" member of Daule formation near Jerusalem,
f,
Daule Basin, Ecuador.
Further material from localities
I,P.C. 538, 755, 774, 7500-A, 7498 (Progreso formation),
1080, 1162, 1461, 1463, 3439 (Daule formation).
.^FZls®l-M
infracarinata Grzybowski, subsp. Nov.
(Plate 6, fig, 12)
Description (based on five incomplete specimens);
shell identical with typical T. infracarinata in sculpture
and ontogenetic development of early whorls, pleural angle,
growth-lines, and thickness of shell material*
The fifth,
sixth, and seventh (earliest seen) spire whorls are pseudo-
bicostate and identical in all respects with corresponding
whorls of T* infracarinata. From the seventh to the sixteenth whorl (latest seen), the subspecies maintains the
bicarinate whorl profile; whereas, from the seventh whorl
on, true Infracarinata loses the bicarinate aspect by the
progressive diminishing of the posterior primary rib.
Com-
parison of the sculpture formulae of the 16th whorl of the
subspecies and the corresponding whorl of a specimen from
the Daule formation is ss follows;
159
CULj^TI
FOR'vULAS
T,
T. Infracarinata
Infracarinata subsp. Nov.
3 (adjacent to suture)
3
3
thread
2
3
2
3
II (weak)
2
1 (subdued carina)
2
3 (adjacent to suture)
(Key
thread
II (strong)
2
(periphery)
I
£
thread
"
to forimila: 3
tertiary spiral; 2
I, II * primaries. )
* secondary;
Dimensions of figured specimen: length, 17.7 mm.;
diameter, 7.4 mm*
The new subspecies is identical with typical T.
infracarinata in its early stages, but differs in details
of sculpture on later whorls.
Since the subspecies occurs
in strata older than beds in which occur typical T. infracarinata, it is possible that the subspecies is the ances-
tor. In view of the persistent bicarinate sculpture of the
subspecies, which is modified in
T,
Infracarirata s.s., the
hypothesis of ancestral relationship appears plausible. The
subspecies is recorded only from the Subibaja
Lower Miocene of the Las Masas sector,
formation,
flth it occur Tur-
ritella hubbard! masasensls, Turris (Polystlra) alblda,
guayaaensls,* etc.
J&egasurculs
ur .r"i
i i,,.j
'iurf
-i
■■iju.hrrimiTniii 3,mmm*mmmwm*mi»m^<mmim:
'mm
■■ "itmmm
fine silty sandstone.
The enclosing
** strata are
Ir
The subspecies Is not given a name,
because no specimen at hand Is complete or mature, and in-
sufficient specimens are available.
160
Material: hypotype no. 20452, Paleontologleal Research
institution, and four additional specimens from locality I.P.C
877, vicinity of Las Mesas, northeastern Progreso Basin,
Turritella hubbardl Hodson subsp, masasensls
Marks., subsp.
nov
(Plate 6, fig. 11)
Description (based on holotype and two pare types);
shell elongate, strongly sculptured, with pleural angle
about
10°. Nucleus
not known.
Early whorls with spiral
sculpture of three coarse cords, the posterior
one adjacent
to the suture, the anterior two separatee from It by a deep,
concave trough, with the central cord strongest.
Adult
whorls with spiral sculpture of three coarse, noded cords
and weak secondary threads; the posterior cord separated
from the suture with an Intermediate transversely striated
secondary thread; the central trough with
a weak, noded
secondary thread and a tertiary thread before and after
the secondary; %im anterior pair of spirals heavy, forming
a double carina, the anterior one slightly heavier, the cen-
tral one heavily noded, futures impressed*
features not known.
Growth-Unas' single-sinused, moderately
concave, with growth-line angle
length (about four
.Aperture!
12°.
Dimensions of holotype;
spire whorls), 20.3 mm,; diameter,
9,6 Him.
The posterior cord of the anterior pair is strongest
on young whorls, suggesting a mesocostate nepionic whorl
profile, as mentioned by Hodson for T. hubbardl (Bull* imer*
Paleo*, vol. 11, no. 45 5 p. 184).
T. hubbardl appears to be
161
quite unrelated to any other group of Turritellas: the
bination of mesocostate nepionic whorls, shallow
com-
growth-
line angle, and strong sculpture appears on no other species
known to tha writer.
"stocks*
T. hubbardl does not fit in any of the
proposed by Merriam,
1941.
The subspecies mm
T. masasensis differs from T. hubbardl
:......".. ..
m
iillilliiliiili.ilI. Hl.iill !ll
i
._«.
IlUIII.
»■■ IJ.I..PIPL
»
i.Mpt
s.s, in Its narrower pleural angle and weaker secondary
spiral ornamentation.
Turritella hubbardl Hodson and subspecies T. weeks!
Hodson are from the
Lower —Miocene
of Falcon and Sulla, Venezuela.
strata of the States
Turritella hubbardl Kodson
in Olsson (1932, p. 203, pl. 23, figs. 1, 2) Is from the
*probably Upper Heath shales'* (op. cit,, p. 204) of north-
?
westsrn
Peru,
The Heath shales are the uppermost Oligocene
formation of that region, Olsson also records T. hubbardl
frotn the lower Heath and the Haaoora formations, Oligocene
(1931, p. 76),
The currant occurrence of the subspecies
Z* masasensis is
1* hubbardl
thus the first record of a subspecies of
in the Miocene of the west coast of south
.America*
2» hubbardl masasensis^ is known
only from locality
1.P.0. 877 in the subibaja formation of the Las Masas sector,
northern Progreso
Basin.
""
(Polystira)
It occurs with Turris
*
..
'
nil.. Twiii'Jn
ujum'Mmfm
I
i|!l.
nnun I|m Bit
JILIILI-HiITIJIIXIIIIW
alblda, Megasurcula guayassnsla, Fusiturrleula delgada, etc.
In a matrix of fine sllty sandstone.
for the
village
of Las Liases,
,
The subspecies is named
162
Material: holotype no. 20453, Paleontologies! Hesearch Institution, and paratypes no. 20454 (2 specimens),
from locality I.P.C, 877, vicinity of 'Las Masas, northern
Progreso
Basin.
Turritella prenuncla Spieker
prenuncla Spieker, 1922, Johns Hopkins Uni v.
Studies in Oeol., 80, 3, p. 81, pl. 4, figs. 1-3;
Turritella
Olsson, 1932, Bull, Amer, Paleontology, vol. 19,
Ho. 68, p, 192, pl. 23, figs 8, 9.
.
Turritella prenuncla is a species of small to
mmm■im»iw m*mm#mmmmmmmmmm.mi
mmmmmmmmimmmimmmmmmmm
moderate size with
tjniform
spiral sculpture.
It may be
closely related to Turrltelle infracarinata, differing
from the latter mainly in its smaller sise and less
carinate whorl profile.
In Peru this species occurs in the Lower Zorrites
formation (Olsson, 1932,
p. 195).
Its only known occur-
rence in Ecuador is in the central part of the Baule
formation at Locality I.P.C. 1458.
163
Family Cerlthiidae
Genus Potamldes Brongniart, 1810
Type (by monotypy), Potamldes lsmarokl Brongniart,
Oligocene, Prance, fide Pilsbry and Beguasrt, 1927, p, 245.
Potamldes Infraliratus Spieker
Potamldes ormel Maury var. Infraliratus Spieker, 1922, Johns
Hopkins Ohlv. , Studies in Geol. , no. 3, p. 58, pl. 2,
fig* 11.
Spieker, Olsson, 1932, Bull.
Potamldes Infraliratus
Taleo *7~voT,' I§ ,""p. 193, pl. 23, figs. 5, 12.
Airier,
The slightly forward-inflected anterior portion of
the outer lip and the small, truncated anterior canal seem
to relate the species closely but not exactly to Potamldes,
-
s.s.
The columellar region has some Cerithldae like charac-
ters.
The species is apparently best left unreferred to a
sub-genus.
The strong, noded sculpture is distinctive.
lar ornamentation may be seen on P.
Sim!
papaveraocue Basterot,
Miocene of France, and on P. triclnctus srocchl, Pliocene of
Belgium.
The two
£♥ infraliratus.
European
species differ in other
As mentioned by Spieker, P.
ways from
suprasuleatua
(Gabb) from the Santo Domingo Pliocene (Pilsbry, 1922, p. 373)
is a closely related species.
In. Peru, P. infraliratus occurs In the Variegated
beds of the Zorritos group, Lower Miocene (Olsson, op. cit.,
p. 194).
In Ecuador the species is found in the basal 23
feet of the progreso formation, Middle Miocene, and In the
nßlue
silt stone" member of the Baule formation, Middle
.
Miocene
164
Material; specimens from the
xaeachtfn corehole,
depths 35-45 and 45-55 feet, and localities 1.P.0. 1134
and 1437.
Family Cypraeidae
Gemis
£££raea
Linne, 1758
Type (by subsequent designation, Montfort, 1810),
Cypres tigris Linns', Recent, Indo-Paeifie,
Cypraea
mm>mmmmmmm^vi wmm\
®**
cf.
C,
mmm
henekeni
mm* mum*■ mm'om<.»«t*mn<mm\m
sower by
Cypraea henekeni Sowerby, 1849, quart, Jour. Geol. soc,
London, voITT, p. 45, pl. 9, fig, 3*
A comprehensive synonymy of C. henekeni is given In
Miury, 19*5, Bail. Amer* Paleo,, vol. 10, p. 219.
Material; one specimen from locality I.P.C. 1464,
Jerusalem sector, Daule Basin, Ecuador; **Blue siltstone"
member of the Baule formation, Middle Miocene*
Cypraea sp.
Locality 1464,
nßlue
slltstoneH member of the Baule
formation, Middle Miocene, Ecuador*
Family Flcidae
Conus ?icus Hiding, 1798
Type (by
tautonymy), Bulla ficus Gmelln, Recent,
Indo-Pacific.
Icus sp.
k rather
sisal! species of Picus is one of the oomnson
165
mollusics of the Subibaja formation in the northern .portion
of the Progreso Basin,
It Is distinguished by a moderately
high spire on which closely spaced radial riblets
in strength to tha primary spiral threads,
are equal
ilia sculpture
of the body whorl consists of strong, raised primary
,
spirals crossed by radial threads of secondary strength
each pair interspersed with three secondary spirals, with
tertiary spirals between the larger' threads.
pattern Is elongate rectangular.
The resulting
Length of a large specimen,
locality I.P.C. 11304 (nearly oomplete), 33.7 mm,
Material
recorded at localities I.P.C. 11091-11093, 11204, etc., all
In the Subibaja formation of the CavrlsaX m& Las tineas sectors.
Family Cassididae
Oenus seonsla Gray, 1847
Type (by original designation), Cassldarla striata
Lamarck, Recent, last Indies.
Sconsia sp
(Plate 7, fig. 14)
of «*»».
Sconsia with the nucleus and
specimen
A single
-,m
mm
-nt n..i».i-p»i,.i m,
anterior extremity missing was found at locality 11120 In
the Lower- Miocene Subibaja formation*
The species Is dis-
tinct from any so far described, but is not here named berate,
cause only one moderately well preserved specimen is at hand.
The shell Is rather small, with spire low and body-whorl
166
broad for the
The sculpture consists of low, closely
genus*
spaced, rather irregular spiral bands, faint, indented growth-
lines, and an incipient varix*
The outer lip has low den-
ticulations and tha anterior portion of the parietal wall
is Urate,
A slight angulation exists on the posterior part
of the body whorl, caused by a swelling beneath 3 spiral bands*
The posterior extremity of the outer lip joins the body whorl
at an angle of about 65 degrees fro® vertical,
A posterior
sutural collar is present* Dimensions of specimen; length
(nearly complete), 33.6 mm,; minimum diameter, 13.4 iam.|
maximum diameter, 24.8 mm*
The specimen appears similar to the example of seoasia
laevigata sowerby figured by Maury, 1917, (p1* 45, fig* 2)
from the Gurabo formation, Middle .Miocene of the Dominican
Bepublic.
Proa this
s. laevigata
the Ecuadorcan specimen
differs mainly by having a swelling about the shoulder, a
sutural collar, a relatively broader body whorl with correspondingly sharper curve at the base of the parietal wall,
and coarser spiral sculpture.
The two are apparently closely
related. More material from Ecuador is needed to show the
true relationship.
from 3. laevigata
of Panama.
The scuadorean specimen is cults distinct
gabs! Olsson from the upper Gatun formation
Specimens of 3. gabb! at Stanford are much more
elongate, with a
narrower, more elliptical aperture, a lower
sutural collar, a less flaring outer lip, and more varied
167
spiral sculpture,
sconsla cocleana olsson from the Lower
Miocene Uscarl shale of Costa Bioa (olsson, 1922 ; p. 310,
pl, 12, fig. 7) Is also a relatively broad species, but
has a low spire, non-angulated shoulder, and no sutural
collar.
Sconsia sp, occurs in the Subibaja formation, Lower
Miocene, where It is associated with Turritella canonista-
dprana and .luorassatella earrlzalenais.
Living sconsla
striata (Lamarck) , a slenderer, lighter calloused species,
is a deep-water form, having been collected from depths of
155 to 255 fathoms near the Bahamas and Cuba (Johnsonia,
no. 9, 1943, p. B}.
Material; hypotype
no. 20455, Paleontologies!
Re-
search institution, from locality I,P.C. 11120, Carrizal
sector, Progreso Basin, southwestern Ecuador.
Family Bursidae
Genus Bursa BOdlng, 1798
Type
ifurex
(by subsequent designation, Jousseaume, 1881),
bufonius Gmelin, Recent, Inao-Paclf ic.
Subgenus liarsupma Ball, 1904
Type (by original designation), Buffo spadiceus
lontfort, Recent, Caribbean Sea.
freya Olsson
aff* B. (Marsuplna)
'.Atmtmiiimtoimmimmwmwmmmmmmmm
Bursa
mmmmmtmMmivmm'
U.
.1
Uuoniiii
i.mnir
j.11
mmm
The Ecuadorean specimen differs from examples of
B* freya from Peru (Olsson, 1932, p. 187, pl. 21, figs. 5,
168
4, 6) only in having three small, pointed nodes between
the varices instead of two broad, low nodes; in all other
respects,
with the possible exception of some apertural
characters which are concealed, It resembles the Peruvian
species. B. chira Olsson (1930, p. 62, pl. 10, figs, 5, 6,
7, 13) of the Peruvian Eocene also has three small intervarical nodes, but is broader and has heavier varices than
either B, freya or the present specimen.
Bursa aff* B, freya occurs at locality I.P.C. 11202
of the subibaja formation, Lower Miocene, Las Maaas sector,
Progreso
Basin. Material; one specimen*
Family Cyxaatiidae
Genus Distorslo Hiding, 1798
Type (by subsequent designation, Pilsbry, 1922),
Distorslo anus (Linne")
(Murex anus Linns').
Distorslo SP*
Fragmentary specimens of a moderately large Pis'L";u'"l
torsio were found at localities I.P.C. 2558 and 11205 In
the Subibaja formation, Lower Miocene, of the Las Maaas
sector, Progreso Basin, Ecuador.
Suborder RACK! GLOSSA
Family Pyrenldae
Oenus Stromblna Morch, 1852
Type (by subsequent
designation, Cossmann, 1901),
Celumbella lanceolate sowerby, Recent, Pacific coast of
tropical America.
169
Marks,* sp.
~ nov,
Stromblna cimarroma
iiiimiiii
■
,p.-.i,-i,.ii.ip
mini
inn
Hii
ipi
mi
(Plate 7, fig. 4}
Description (based on holotype and one fragmentary
paratype); shell slenderly biconical, moderately small;
nucleus of three broad, smooth whorls, with apical angle
of about 58 degrees; spire whorls five in number, the first
two nearly flat-sided In profile, the latter three convex,
all about twice as broad as long, and forming pleural angle
of about 32 degrees; body whorl elongate, about 55 per cent
of total length of shell; axial sculpture of strong, uniform
folds consisting of twelve slightly retroeurrent folds on
first two spire whorls and eleven vertical, baaaily swollen
folds on remaining whorls, lacking on back of body whorl
except for a strong varix just dorsal to outer lip;
no
spiral sculpture except on base of body whorl; sculpture
of base consisting of 11 raised spirals, finest at anterior
extremity; sutures impressed, slightly deflected at intersections with axial folds; aperture narrow, vertical, subquadrate; columella vertical, covered by moderately heavy
callus, supporting seven broad, low liratlons; parietal wall
thinly callous; outer lip sinuous, thin, vertical in profile,
with a slight posterior notch, backed by a varix, internally
thickened below posterior notch and having six strong denticles; siphons! notch deep, at an angle to aperture! face.
Dimensions of holotype: length 11.8
mm*,
maximum diameter
4*2 mm,, minimum diameter 3*7 mm*, length of aperture 3.3
jam.
, width 1.3 mm.
170
Ho significant variations from the features shown
on the holotype are present In the paratype, a slightly
worn
specimen that lacks the body whorl.
-
*»
The new species is distinguished by its slender
form, persistent axial sculpture and short aperture.
chief differences between B* cimarroma and
The
s. laneeolata
(Sowerby), type of the genus, are; 3. clmarroaa has a
nucleus of three rounded whorls, followed by the regularly
sculptured spire ifhorls,* whereas 3* m*>mtimmmmmm*m**\
lanceolata has a nucleus
m*
*m
mmt
1. 1mmm**mmmtmm
of ljr blunt whorls, followed by an apparently bare first
spire whorl, then by low, barely discernible, irregularly
spaced axial folds that on later whorls develop Into nodu-
lar ribs*
* limited parleS. cimarroma nas a well-defined,
mmm
mm*mmmmmmmmmmmmmmmmmmmtm
tal callus, whereas
mt
s. lanceolata has callus
extending in
a heavy wash far out over the parietal region and blending
in with the shell wall at Its extremities,
s. cimarroma
has a better defined posterior notch and a shorter aperture
than 3* lanceolata.
The new species Is not closely related
to any previously described tropical American form.
The type specimens occur in silty shale about 1460
feet above the base of the Subibaja formation, Lower Miocene,
associated with a small Terebra*
habited the deep nerltio zone*
The species probably inThe trivial name "cimarroma"
is derived from the Spanish "cizoa," summit or apex, and
"roma," obtuse or blunt, with reference to the large apical
171
angle of the
nuclear whorls.
Type material, holotype
no. 20456 and paratype
no,
20457, Paleontological Research Institution, from the
;iacachun corehole, depth 400-410
feet.
Strp.mbl.na striatoco state, sp, no v.
(Plate 7, fig, 7)
Description (based on holotype and 12 paratypss):
shell blconic, of moderate size,
whorls, oblique to axis of shell,
number.
nucleus of three barren
spire whorls eight in
Axial sculpture of thin ribs, about 18 on the
penultimate whorl, nona observed on tha first two spira
whorls, and of two vsrlx-llk* swellings on the body whorl
in addition to the swollen outer lip. Spiral sculpture
of three to five faintly impressed lines that cross the
axials,
Sutures abutting.
Aperture with callus thin
on
parietal wall, thick and well defined on columella; and
with swollan outer lip that has an interior reinforcement
carrying four or five low, swollen dentloulationa, with
two or three more doat! eolations anterior to the reinforcement.
Anterior canal with deep notch, slightly recurved.
Dimensions of
holotype; length 25,7 mm*
, diameter
9.9 mm.
The largest specimen on hand is 12.5 mm, in diameter.
***"
The new species
is similar to
and Pilsbry from the Gatun
s.
mmm-
formation of
lessepsiana Brom
mmmm-mmxpim
<m*mmm- mmr.iM-mwtmimmmmm-
Panama.
It dif-
fers from the Gatun .species by having heavier axial
172
sculpture.
It has fine spiral sculpture, which
s. lessen-
siana lacks.
§" striatocostatia occurs only in the "Blue silt
stone w member of the Daule formation, Middle Miocene*
Material: holotype
no,
20458, Paleontological Be*
search Institution, from locality I.P.C. 1462, Jerusalem
ssctor, Daule Basin.
from same locality.
Paratypss no, 20459 (three specimens)
Paratopes
no. 20460 (three specimens)
from locality I.P.C. 1464 of same sector.
Paratypss no*
7980 (four specimens) ? Stanford Univ* Paleo. type coll.,
from locality 1080, near Pedro Oarbo*
Further material
from localities I.P.C. 1162 and 1461, near Jerusalem*
Strombina paouenj-ta Marks, sp. Nov.
(Plate 7, fig* 1)
Description (based on holotype and
seven paratypes):
shall small, the maximum height (estimated) about 11.5 mm*,
slender, with little expanded body whorl; nucleus short,
consisting of a "button" and one wide whorl,
first two
spire whorls bare, third with about 12 wide, flattish axial
ribs wider at bottom than top, fourth with about 14 ribs
that reach only to upper 3/4 line of whorl, sixth whorl
similar, seventh whorl with 14 ribs that are larger at
bottom than at top and over-hang the sutural cord; every
spire whorl except the first three having a strong
con-
striction and an ante-sutural swelling or undefined cosd
173
at the top or posterior.
Sutures irregularly apprsssed.
Body whorl sharply Inflated about center line, bare except
for sinuous growth-line traces and about IS raised spiral
cords with flat interspaces of equal width about the base.
Aperture with a thin, discontinuous parietal callus, den-
ticulate on columella, strongly lirate on Interior of outer
lip; outer lip thickened dorsally; anterior canal missing.
Variation in strength of axial ribs and sutural cord noted,
the extreme case having barely discernible ribs and a relatively stronger
cord,
Holotype largest specimen, next
largest (nearly complete) measuring only 8.7 mm.
smaller specimens are probably not mature.
The
Dimensions of
holotype; length (incomplete) 10.0 ram., diameter 4.5 mm*
The new species is distinguished by its anteriorly
related to only s* dauleswollen axial ribs. It is closely
w
w
mmm*
i.tmmmim^irtm.mmmm
chica (q.v,).
§* pcquenlta occurs in the uppermost strata of the
Subibaja formation, Lower Miocene,
Material; holotype no.
20461, Paleontological Re-
search Institution, from the Zacachun corehole, depth 80-90
feet,
Paratype
locality,
no. 20462 (six specimens) from the same
paratype no. 7981 in the Stanford University
Paleontology collection, from the same locality.
174
Stromblna daulechiea Harks, sp.
Nov.
(Plate 7, fig. 5)
Description (based
on holotype and 22 paratypes);
shell small, the maximum height 11 mm,, slender, with expanded outer lip and two varix-llke swellings on the body
whorl,
nucleus and early nhorls similar to those of S.
pequenlta.
Axial sculpture evanescent on fourth spire
whorl. Dimensions of holotype: length 9.5 mm*, diameter
4.0 mm.
is similar to S. pequenlta In Its
J£«
early stages, but loses the anteriorly swollen axial ribs
on the fourth spire whorl, whereas the axial ribs persist
on jh pequenita.
The aperture of
s. daulechiea
la heavily
calloused, a feature not preserved or undeveloped on the
examples of
s. pequenlta*
The specimens of
s.
daulechiea
are nature individuals.
" daulechiea is known to
ties.
occur at only two locall
These are in the "Blue siltstone" member of the Daule
formation, Middle
Miocene,
Material; holotype
numerous
specimens
occur together.
no. 20463, Paleontological Research
Institution, from locality I.P.C. 1462, near Jerusalem,
Daule Basin,
from,
gcuador.
Paratypes no. 20464 (20 specimens)
the same locality,
Paratypes no. 7982 (four specimens)
in the Stanford University Paleontology collection, from
locality I.P.C. 1461 in the same sector.
175
Cenus Anachls H* and A* Adams, 1858
Type (by subsequent designation, Tate, 1880],
colum-
balla sealsrlna Sower by, Hecent, Panama.
Subgenus
Costoanachls sacco, 1890
Type (by subsequent designation, Pace, 1902), Colum-
balla (Anachls) tmrrita Sacco, Miocene, Italy.
Anachls ( Co stpanachl.s ) steyensoni Marks, sp. Nov.
(Plate 7, fig. 6)
Description (based on holotype and two fragmentary
paratypes); shell small, slender, -sculptured with strong
axial ribs. Nucleus wide, consisting of a "button" and
about one whorl.
Spire whorls six and one-half in number,
with pleural angle of 32 degrees: first two and one-half
whorls bare, earliest sculpture of prominent, strongly
antecurrent axial ribs becoming vertical within one-half
of a revolution, numbering 12 on the first sculptured whorl;
adult axial sculpture of 15 ribs on penultimate whorl;
spiral sculpture ot 10 well-defined cords on pillar, with
two more poorly defined cords on bast of body whorl. Base
of body whorl slightly constricted. Sutures impressed,
slightly fluctuating.
elongate
Interior of outer lip with six
denticulatlons (apertural margin broken).
ella with callus and five low denticulatlons*
canal slightly twisted to left (tip broken).
length 7.5 mm* , diameter 3.0
ma.
Colum-
Anterior
Dimensions;
176
As here used, Costoanachls prescribes to the de-
scription of Woodrlng (1928, p. 276); "...small, axially
sculptured columbellids that have at least some trace of
.
an anterior canal. ,sone are so large or so stout as
Anachls
s,s."
Several species of Costoanachls have been
recorded as occurring In the Miocene of the Caribbean re-
gion, but none of these is identical with the scuadorean
species.
The new species is known only from the upper
Lower Miocene of southwestern Ecuador, where it occurs in
siltstone associated with Nuculana (gaccells) sublbajana,
etc.
Material: holotype no. 20465, Paleontological Research institution, from the Zacachun corehole, depth 80-90 feet, Zacachun sector, Progreso Basin, from the Subibaja
formation, 1730 feet stratigraphically above the base of the
formation.
Family $assarildae
Genus Phos Montfort, 1810
Type (by original designation), fgur ®x
sen11cosue
Linne', Hecent, Indo-Pacific.
Phos cf * P. tuberaenals .Anderson
(Plate 7, fig. 2)
Cf. Phos tubara^nsls Anderson, 1929, Proc. California Acad.
§(517, "Ter. '4," vol. 18, no. 4, p. 135, pl. 9, figs, 1,2,3.
The iscuadorean species is more sharply sculptured
177
.
than P. tuberae'ns is The one specimen available is smaller
than Anderson* s specimens, which are about 50
jas.
long.
Dimensions of the figured specimen; length (incomplete)
25*2
an*,
-A-ldth 15*0 mm.
£" c*» &" tubera&asis occurs at locality
I.P.C.
11204 in the Subibaja formation, Lower Miocene, of the
Las Mesas sector, Progreso Basin.
The unique representa-
tive is hypotype no. 20466, Paleontologies! Research Institution,
jpa
Phos
haughti Marks,
sp*
nov.
(Plate 7, fig, 9)
Description (based on holotype and about 15 paratypes); shell of moderate size, broadly blconleal, with
pleural angle (excepting body whorl) about 50 degrees.
Nucleus elongate,
earliest sculpture of about 8 axial
swellings per whorl.
axial swelling®
Adult sculpture of eight strong
per whorl that become quite pointed on
back of body ??horl and are crossed by a strong peripheral
spiral thread, with two primary, threads anteriorly and tiro
weaker threads posteriorly, and- by occasional weak secondary
spirals.
Body whorl with 11 primary threads below
periphery, and a thin thread, a strong cord, and three or
four weaker cords on the siphonal fascicle,
sutures im-
pressed, formed by overlap of later whorls.
Parietal wall
thinly calloused; columella with a groove and a strong
plait; outer lip thin, wrinkled exteriorly, carrying about
178
twelve irregularly spaced iirae anteriorly, and with a
slight inversion opposite the end of the columellar plait.
Anterior canal short, deeply notched. No anal sinus.
Dimensions of holotype: length 43,6 mm,, diameter 23.7 ma.
Variations noted In amount of overlap of succeeding whorls
snd
,
therefore, in number of exposed primary spirals on
■
spire whorls.
The new species is most closely related to p.
veatchi Olsson of the Costa Pica and Gatun isiocene. It
differs from P. veatchi by being shorter, broader, and
more strongly sculptured,
P. haughti is known to occur
only In the "Bins siitsstorme n msnber of the Daule forma-
tion, middle Miocene,
The species Is named for 0* L.
Haught, geologist and collector of the type specimens.
Material: holotype no, 20467, palaontological Hesearch institution, from locality I.P.C. 1464, near the
village of Jeruaalani, Daule Basin, southwestern Ecuador.
Paratypes no. 20468 from locality 1464.
Paratypes no,
7984, Stanford Univ. Paleo. coll., from locality I.P.C.
1162, near tha village of Jerusalem, Daule Basin, Ecuador.
Further paratyple material from localities 1080 . 1134,
1462, and 1463.
Baaus Tritiaria Conrad, 1865
Type (by
Upper 15o cone,
monotypy), Buceinum ml salssippi.Ansis Conrad,
Mississippi.
179
Subgenus Antlllophos Woodring, 1928
Type (by original designation), canoellarla oandel
d*orb,, Hecent, lest Indies.
Trltiarla (Antlllophos) landesi Marks, sp.
Nov.
(Plats 8, figs. 1, 2)
Description (based on holotype and 8 paratypes);
.hell .lender, with pleural angle ot about
30°;
nucleu.
consisting of about 3| broad whorls with apical angle
75°,
the last half-whorl having 4 fine spiral threads; spire
whorl®
about
generally 4 in number (3
3/4
as wide as long,
on holotype); body whorl
sculpture pattern of rounded
spiral threads and strong axial ribs; earliest sculpture
(on protoconch) consisting of four fine spirals: these are
augmented on later whorls by similar spirals rising from
the anterior suture, the maximum number being 8; some fine
intermediate secondary spirals present.
Axial sculpture
developed suddenly on earliest spire whorl as strong, pro-
taactive riblets; on later whorls these become vertical or
slightly rstrocurrent , fourteen on penultimate whorl,
crowded and occasionally varix-like on back of body whorl.
Aperture sub-ovate, inclined at 17-degree angle to axis of
shell; columella lightly calloused, with weak denticulatlons caused by continuations of spiral threads beneath
callus; outer lip with thin e6^e f interiorly Urate; an-
terior canal short, barely recurved; no anal notch.
Slphonal fascicle barely raised, separated from columellar
180
callus by slight impression or umbilicus.
slight stromboid notch.
Outer lip with
Dimensions of holotype; length
15.4 mm., diameter 6.7 mm. Dimensions of largest paratype; length 17,8 mm., diameter 7.8 mm,
Trltiarla landesi Is placed in Antlllophos because
of its large nucleus, early axial sculpture of protractive
riblets, denticulate inner lip, and nearly straight anterior canal.
It lacks the strong slphonal fascicle and
recurved canal of Phos.
It has early spiral sculpture,
rather than axial sculpture as has Trltiarla s.s.
The
closest described species is apparently T. (Antlllophos)
slogans llmonensls (Olsson) from the Miocene of Costa Rica,
which has a longer anterior canal, weaker axial sculpture,
and more parietal callus.
Tritiaria landesi occurs at 3 localities in the
Lower Miocene Subibaja formation of the Las Masas sector.
The exact etratigraphle position within the formation is
not known.
The enclosing strata are siltstone and fine
silty sandstone.
■P
Associated with T. landesi are
«p>p*p>-
-i i,.iu.,.ii»ni,j«---- im
,p»pp»
Megasuri.„..,»,pp»7ii,p-..,i,i;,»,-J»»-.
eula guayassnsia , Conus masassnsia , C. rolgl, Turrls vanaiblda,
ingeni,* T. mummm
* etc.
m
■mm^mmfaumF.
—i I
mmm
>>m,m.mmmm -i
i
The species
"**
is named for B* W.
Landes, who mapped most of the Progreso Basin and collected
the
type
material.
Material: holotype no. 20469, Paleonto logical Research Institution, and paratypes no. 20470
(3
specimens)
181
from locality I,P.C. 11205, near Las Hssas, northeastern
Progreso
Basin.
Paratype
no. 20471 from locality 2558.
Paratypes no* 20472 (2 specimens) from locality 11203,
Paratypes
no. 7985 (2 specimens), Stanford
llniv,
Paleo*
type coll., from locality 11203,
Trltiarla (Antlllophos) mcxicans (Boss)
Phos aexloanus BOse, 1906, 801, Inst. Oeol. Mexico, no,
"""2*2', p. 317 pl* a. figs. 18-21, Olsson, 1922, Bull.
Ansr. Paleo., vol. 9, p. 117 , pl, 9 S figs, 10. 11.
Phos (Antlllophos) mcxic anus B&se, Oinomlkado, 1939,
Jour, CkJSiT"Soc. Japan, vol, 46, no. 555, p. 622,
pl, 29, fig* 16.
This species occurs in the "Blue siltstone* member
of the Daule formation, Middle Miocene, Material was.col-
lected from localities I.P.C. 1227 and 1684 in the northern
Daule Basin.
(Antlllophos) sp.
Trltiarla
.
■ _i Kiwrni, mi
fTnin— ii? liiriffmur
». 'mmmmc**mmmmn \immmmmm*mmmmmmi
This amall species, with rather blunt spire and
.
fewer spirals than T. landesi
occurs In the medial strata
of the subibaja formation, Lower Miocene, of the Zacachun
sector*
Seven fragmentary specimens were found at depth
70-80 feet in Dos Bocae corehole Ho. 1*
Trltiarla (Antlllophos?} sp.
(Plate 8, fig, 3)
The early whorls of the single specimen are miss
ing and the surface of tha siphonal fasciole Is deeply
182
The shell has the strong axial and finer spiral
worn.
sculpture, the denticulate parietal wall, and the Urate
outer lip described by Woodring for Antillophos.
The
spiral sculpture of the penultimate whorl consists of 5
primary threads, of which the posterior two are closely
proximate; midway between the primary threads, except the
posterior two, are fine secondary threads.
The axial
sculpture of the penultimate whorls consists of 17 strong,
rounded ribs that are spaced slightly irregularly.
All
elements of the sculpture increase in number on the later
whorls.
The parietal callus is heavier than in other
known species of Trltiarla. Dimensions of figured speci-
men: length (incomplete), 13.7 mm., maximum diameter 6.9 mm
This specimen compares very closely with T. mexicana
(BSse)of
the Daule Basin Miocene, differing only in size
and minor details of secondary sculpture.
should be referred to that species.
It possibly
It was found 768-780
feet above the base of the Subibaja formation, Lower Mio-
cene.
Material: hypotype no. 20473, Paleontological Re
search Institution, from the Zacachun corehole, depth
1090-1102 feet, Progreso Basin, southwestern Ecuador.
183
Family Buccinida©
Oenus Cantharus Hoding, 1798
Type (by subsequent designation, Cosssann, 1901),
£* globularis
Boding
t*
Bucclnum tranqueharicum Gmallnj,
Hecent, Indian Ocean,
Subgenus Triumph! s Gray, 1866
Type (hy monotypy), fri umphl s d1storta Cray,
Hecent, West Coast of Central America and northern South
America.
Cantharus (Triumph!s } predistortus Marks, sp.
(Plate 7, figs. 8, 10,
Nov.
Hi
Description (based on holotype and six paratypes }.
shell of moderate siso, low-spired, broad,
with pleural angle of about
77*** Nucleus not known*
Earliest sculpture of 8 strong axial folds per whorl,
crossed by 3 strong, primary cords.
Axial folds de-
creasing In strength on penultimate whorl, disappearing on last quarter-turn*
Spiral sculpture of three
strong cords on early whorls, augmented by two inter-
calated secondaries,
a posterior secondary, and two
or three anterior secondaries on tha later spire -wtxorls*
184
continuing as low, weak spirals on shoulder of body whorl.
Base of body whorl with about 18 incised, irregularly
spaced spiral lines.
hump
Shoulder of body whorl with distinct
near aperture and thin, inclined buccal margin.
Aper-
ture with strong parietal callus, deeply notched anterior
canal, slight anal notch. Outer lip marginally serrate,
protractive about center, retractive against suture, thin
on edge where serrate.
Columella with raised, sharp
siphonal fascicle and slight umbilicus.
type; length 46.6 mm,, diameter 27*5
Cantharus
Dimensions of holo-
mm.
(Triumphis) distortus, Hecent, type of
Triumph!s Gray, is probably the descendant of 0. prodlstortus;
it has the same features in but slightly changed
*m*-mmm m*\U Wmt
C. distortus has two instead of three strong pri-
degree.
maries on early spire whorls, and more numerous secondary
spirals. It has a less pronounced hump on the shoulder of
the body whorl than C* predistortus, the anal notoh Is less
pronounced and more distant from the suture, and the basal
spirals are much heavier.
.
(Grzybowsky)
guttiferus
from
' Jmtmmmm
*
*
cantharus (Trlumphis)
m
"m
■
i. n.in
ii
in
mi
tiii.
«,,.p.i
r.«.»
1,,,)
iijfriii mi Hm i
i mi
.nni
the Middle Miocene of Peru and another very similar species
from the basal Gatun formation of Panama apparently repre-
sent a lineage distinct from that of C. predistortus.
Their
lineage apparently did not survive, since no Recent species
closely resembles the Peruvian and Panamanian species.
185
£*
pyedistortus is known to
occur only In the Middle
Miocene uaule formation of Ecuador.
Material; holotype
no. 20474, Paleontological
Re-
search Institution, from locality I.P.C. 3439 in the north-
ern part of the Daule Basin about 20 km. H 81°
Manabi Province.
Paratype
„
of Calceta,
no. 20475 from locality I.P.C*
1458, near the village of Jerusalem.
Paratypes
nos. 20476-
-20479 from localities I.P.C. 1080, 1437 (figured), 1458,
and 1464, respectively, from the Daule Basin*
Paratype
no.
7986, Stanford Univ. Paleo, type coll., from locality 1080.
Oenus Hanatla Jousseaume, 1880
Type (by original designation), Murex hanetl Petit,
.Recent,
Brazil.
Hanetia sp.
(Plate 7, figs. 12, 13)
A moderately large Hanetia ("pSolenostelra") occurs
in the "Blue slltstone** member of the Daule formation, Middle Miocene.
.
(Brown
and Pilsbry)
'
* of
It resembles mm
B* dalll
n»
W
I
iii.
the Qatun formation, but has a shorter canal, larger spire,
and less salient axial ribs than H.
dalll*
mm
mmmmmmmmmmmmm
Material: hypotype no. 20480 , Paleontological Research Institution, from locality I.P.C. 1162, Daule Basin,
Ecuador. Further specimens from localities
(one specimen) and ICBO (four specimens).
I.P.C,
1162
186
Genus Melongena Schumacher, 1817
Type (by original designation), Blurex melongena LinnC.
Melongena oolombiana Weisbord
*
Melongena Colombians ieisbord, 1929, Bull.
amer. Paleo.,
~vol.""lTrpu 275» Pl- '. figa. 2-4. Olsson, 1932, Ibid.,
vol. 19, p. 177, pl. 19, fig. 1.
*
A single poorly preserved specimen from the fßasal
calcareous* (lower) member of the Baule formation, Piddle
Miocene, apparently is this species.
M* Colombians also
occurs In Peru, in the Variegated beds of the Sorritos
group, Lower Miocene.
Material; one specimen, height
107 mm* , from local
ity I.P.C. 1232, Rio Panchal section, Daule Basin.
Melongena sp.
nmrnwrs"*-" wiWiuum'
■imttmmmmmmmm
■***
A single specimen from the base of
mation near Zacachun, too poorly
the
Progreso
preserved for
for-
identifica-
tion, is similar to M^ consors Sowerby or M* Colombians
ieisbord.
Material; one specimen, height (nearly eomjjlete)
91 mm,, from locality I.P.C. 7618, south of Zacachun.
Family Muricidae
00111113 yitularla Swalnson, 1840
'* W?**
Type (by monotypy), yitularla tuberculata Swainson
mlliarls Gmelln), Hecent, West Africa.
187
Titularla
ecuadorana
mummm
—"■"—'■■-■■"
]■■
:i -ii
-11*11111
~.rf.irt>*,i"iu'ii mipvwmatmmm
Marks,
* sp. Nov.
*-
(Plate 8, fig. 12)
Description (based on the holotype); shell of moder
ate sisse, thick-walled, ornamented with eight or nine
raised, oblique, longitudinal ribs per whorl, nucleus of
14
turns.
Spire of slightly more than 2§ turns.
Outer
lip thickened, with 11 internal teeth. Aperture narrow,
..a
elongate, sub-ovate. Columella straight, breached at base.
Dimensions; length 59.4 mm*
, diameter
30.0 mm.
Tha Seuadorean species differs from the ascent V*
salebrosa King of the test Coast by having a higher spire,
a larger portion of the spire whorls exposed between the
periphery and the anterior suture, a
narrower, more angled
aperture, and a more angulated periphery.
type of the genus,* has
mm
iw*
V. my^arls.
*
a lower spire than V. ecuadorana,
,
«*
pii.ii.iii.,
,i-,...,,p
i-.iiiiiihiiimmw
more swollen axial sculpture, and a shorter, broader aper*lt -,fl
The oldest horizon in tropical America from which
the genua Vltul*rl* has been record.* i.the Pliocene
Charoo Azul formation of Costa Pica, from where V. cf,
v.
salebrosa King was obtained by Olsson (1942, p. 170).
The
present
occurrence of V. ecuadorana extends the range of
the genus to the Middle Miocene.
The holotype and sole specimen was found at I.P.C.
locality 1080 In the Daule formation, Middle Miocene.
188
Materials
holotype no. 204-81, Paleontologies! He*
search Institution,
Family Thsisidse
mmmm
Chorus Oray. 1847
Type ("by original assignation}, i
res glganteus
Lesson, Bseent, Chile,
Chorus aula suhsp. orusiana f Olsson }
Aeanthisa (Chorus j .suls eruslana Olsson, 1932, Bull* Alter,
Safes*, vol. 19, p. 185, pl, 20, .fig. 7.
*° £*
Thro©
rather poorly preserved specimens referable
c.rusl&na occur at locality I.P.C. 508 in the type
Progreso formation, Middle Miocene,
fhey compare Closely
with 0. gifianteua .Lesson, type of the genus, differing from
It principally by having a sharper, narrower shoulder and
smoother sculpture.
The aperture la not visible.
The
largest fragnsnt would have a length of at least 65 sa.
Xn Peru, the species has been noted in the Lower
Zorritos f ormstion, Lower Miocene,
Occurrences were also
noted In the Lower Miocene Subibaja formation of the- Las
Bases and Carrla&l sectors, whore the material consists
mostly -of internal soIds.
Family FSselolarildae
8*bus Pasololarla Lamarck,. 1799
Type (by sonotypy), ferax tulipa
Caribbean Sea.
Linni* Secant,
Fasciolarla? sp,
*»api«pmp».....i,..n.,.i..«p..p,.»ii
ii imi i,iiii-m»
A single specimen from the base of the Progreso fovulation, Middle Miocene, is similar in appearance to Pascio-
189
type
(Llnn4),
of the
*
larla tulips
,„„,
mm
■ipiiiiHpipl»iliiiiiiipp...'.i
..p.
,„i.
.A,,.,—
*W
genus*
*>*
It is too
poorly preserved to be surely identified with a known
.
species
The badly worn whorls appear to be worm strong-
ly unguis ted than those of
£
.
.
fculipe, f
Sowerby of the Dominican Wlocene, or
Vaodring of th©
©f
BoMen Miocene*
semi striata
£. aeat!striata
leurm
There Is a suggestion
spiral ornamentation on the spire whorls. Dimensions?
length (lower half of body whorl and anterior canal HissingIt &1
a®..;
diameter (nearly complete) 43.8
materials
one specimen free locality
south of Zacachdn, Progreso Basin,
mm*
I*F,C. 761
a,
190
Suborder TOXOGLOSSA
Fami ly Cancellarlidae
About thirty species
f eancellarilds wore- noted In
the Miocene sediments of the Progreso and Daule Basins,
Most of the
examples are too
poorly preserved for specific
identification or assiipiaent to a sub "generic unit. Four
f these species have been described and published*1 For
m- w-wm, <m m m*m m.mmm mm m.m.mm.mm.mm.mmum«"
1
Harks, J, 0., "Bemenelatural units and tropical American
Viocene species e-f the gastropod family Cane® liar!Idaa**,
Jour. Paleontology, vol. 25, 80. S, pp. 453-454, pl. H,
September, 1940.
the sake of completeness, a
sussMiry
of their classifies*
tion and stratlgraphic occurrence Is presented below.
Genus Cansallaria Lamarck, 1799
Type (by monotypy).
Volute reticulata Llnnl, Resent,
Caribbean Sea*
Subgenus
Cancellaria. sensn strict©
*pancellarla s* s. is a prewalent stock in
the Iropical' America« iiooene strata, At least
mix spec!as are known to occur. There arc,
for example, at least four species, represented as yet by specimens too badly preserved to
be described, in the Scuadorsan middle and lower
Miocene." 2
p**««p»«aH*«..*
2
«« v ** aaa«,. wva
9
Op* cit* , p. 461
191
Cancellaria {Cancellarla j sursalts Marks
Cancellerla (Cancellarla j sursalts Marks, 1949, Jour.
Baleontology, vol. 25, la* 5, p. 461, pl. 78, fig. 4,
"This small, neatly sculptured species is related to C, (Cancellarla ) dariena of the Gatun
formation"^ Panama }*
It differs from C. dariena
a more turreted""spire and
having
by
principally
regular axial sculpture, with no tendency to
form varices. It is assigned to the subgenus
Cancellarla chiefly because of its evenly con*
vexi cancellate early spire whorls, elongate
shape, and aperture! characters.
C. (Cancellaria j sursalts occurs near the top
of tlie lower Miocene strata of southwestern
Ecuador, at a horison possibly represented in
the lowermost beds of the Gatun formation of
Panama, A species of Cancellarla (Cancellarla }
found at the lower Gatun borison is even more
closely allied to C. dariena than is C. sursalts,
and 5 s probably the direct antecedent^of C.
darkens. This lower da tun species differs froia
Cv dariena MSinly by being more elongate. An
analogous form, questionably referred to C.
dariena, occurs in the basal Miocene straTa of
northern Ecuador.
W
"Material,
-
Eolotype 10. 20301, Baleontological Research Institution, from the Zacachdn
corehole, depth 140-150 feet, Eacachdn sector, Ouayas
Province (Progreso Basin}, southwestern Ecuador.
Paratypes 10. 2C&92 (two specimens), Paleontologies!
Research Institution; and paratope So* 7966, Stanford. Uni v. Paleo* type coll., fro® the same locality* n 1
****-**
1
Qp. cit** PP* 461-462.
« «" *.
mm
Subgenus Bivetiella Marks
"Biyetiella is represented In the tropical
American Ifiocene by at least
c * (Blvetiolla j eDlstomlfera
tiescribed below, and several
mens from the Miocene strata
belong in the group." 2
2
Op. cit., p. 462.
-
one described species,
Guppy, two more are
badly preserved spec!
of .Ecuador probably
192
Cancellaria (Blvetiellaj
fHzgell'
;.^ks
Cancellarla (Biyetiella j frisselll larks, 1940, Jour.
Paleontology, vol. 25* Mo. 5, p. 462, pl* 78, fig. 6*
w ®*
friß&elli occurs In the middle Miocene
Daule"*forxrsition of southern Ecuador, associated
.
ai^h Potajaldas Infraliratus Spieker, Conus aultlliratus Bose, Bfaculans sp. and other Farias , *
, 1konto
logical He-search Institution, from I.^*l* ty I*f»C*
1437, near the village of Jerusaleis, northernmost Guayas Province. (Baule Basin), Ecuador.
Paratype 10. 7961, Stanford Untv* Paleo. type
coll. /from locality 1457, same sector.* 1
"
1
St*
a ;a,. holotype Ho. £'j?G4
cit* I Pi 4m
■**"**
Cancellaria (B
******
mum****
ella ) santiagensis Marks
Cancellaria (Blvetleila iaantla^ensis larks, 1949, Jour,
P&leentolay^, Val* 85, 10. 5, p. 462, pl. ft, fig* 6.
fhs type specimens of
£*
santia-gensls were found
In the basal Miocene Angostura fowafclaa of northern
coastal Ecuador,
The
species
also occurs In the Lower
Miocene Subibaja formation of southwestern Ecuador in
the Zac&chtSs eorebele* depth 979-980 feet.
Ci ncellaria caslcalva larks
caslcalvs larks, 1949, Jour.
Paleontology, vol, 23, So. ts, p. 464, pl. 78,
figs. 5, 10*
Cancellaria (subgenus?;
w
ea S.ioslvs,
occurs in the middle Miocene
DaulV 'forisalTon of the .Daule Basin, central
£
%
coastal Ecuador*
193
"Material. Holotype no. 00335* Paleontologies! Research Institution, from locality
I.P.C. 1464, Jerusalem sector, northernmost
Guayas Province (Daule Basin), Ecuador.
Paratype no. 20389 (figured j from the same
locality. Paratype no. *?965. Stanford Unlv*
*
Paleo. type coll., from the same locality. 1 1
*
op. cit. *
«■»
*m m* t***■■"*.
464*
m
wt*r."*,''»*' *»
194
Family Terebridae
Oenus Terebra Bruguiere, 1789
Type (by monotypy, Lamarck, 1799), Bucclnum subula-
tum Linne, Recent, Tndo-Paclflc (fide auctt.}.
Subgenus Paraterebra 3oodrlng, 1928
Type (by original
Keeent, Gulf of
designation), Terebra texana Ball,
Mexico and Caribbean Sea.
. T* oucurrupiensis
Terebra (Paraterebra) cf
Ginomlkad©
The isouadorean examples are identical with Oino-
aikado's species, judging by his illustration (1939, p,
626, pl. 29, fig, 1),
The finer sculptural elements are
eroded (e.g., "microscopic spiral threads").
Development
of the axial sculpture answers the written description.
The only detectable difference between the sound orean and
Colombian specimens is that the axial riblets on the lower,
sunken part of the spire whorls of the Bcuadorean material
are inclined somewhat antecurrently, whereas olnomlkado *s
figure shows these riblets to be verticsl.
Specimens com-
pared with T. Qucurrup.iensis in the Thompson collection
from Panama have the anterior portion of tbc axial riblets
even more antecurrently Inclined than the leuadorean speci-
.
T. cf
T. eucurrupienais Is represented by two speci-
mens from localities I.P.C. 1437 and 1457, in the *Blue
aata of
siltstone" member of the Daule formation, Middle Miocene,
near Jerusalem, Daule Basin, Ecuador.
195
Subgenus strioterebrum sacco, 1891
Type (by original designation)
, Terebra basterot!
Nyst*, Miocene, Mediterranean region.
Terebra ( gftj^aforebran) ulloa Olsson
Terebra ( strictersbrum) ulloa olsson, 1932,. Bull, Aaer.
fialeo.", volT"s£7p» IffiHTvl* IS, figs. 1, 2.
A single well-preserved specimen of T. ulloa was
found in the strata 10 feet below the top of the subibaja
formation, Lower Miocene,
The nucleus Is missing.
The
second spire whorl is faintly sculptured with barely
raised a&ial ribs, Spiral sculpture first appears on the
fourth whorl as seven low, rounded spirals that do not cross
the axial ribs.
The fasciolar band first appears on the
The adult sculpture is as described for the
seventh whorl.
type specimens.
T,
ulloa was described from specimens obtained in
the Lower Zorritos formation, Lower Miocene, of northwestern
Peru (olsson,
loc. cit,).
Material; from the Zacachun corehole, depth 68-71
feet, frogreso Basin, southwestern Ecuador.
Terebra cf , T. (strioterebrua) aapotalensis Olsson
c *« Tergbi^ (strioterebrum) zapotalensls Olsson, 1932,
Bull."""Siier." FaleoTT vol, 32, p. 148,' pl. 15, fig. 5.
Several poorly preserved specimens similar to T,
zanolensis were found in the upper strata of the Subibaja
formation, Lower Miocene.
They differ from T. zapotalensla
196
bisinly
in having a heavier posterior collar*
The Peru
visa species occurs in the Lower Zorritos formation of
northwestern Peru (Olsson, loc. cit. ).
Materials
from the SSacaehdn corehole, depths
"00 and 140-150 feet, Progreso Basin, southwestern
c -xador*
197
Family Turridae
Subfamily Turrlnae
Ooaus Turris Rdding, 1798
Type (by subsequent
designation, Ball, 1909), Murex
babylonus Gaella (error for babylonlus )
*
Ifurex
fe£^/lcnius
Linne, Hecent, Indo-Jpaoifio.
The mature individual of Turris baby!on lua Is about
ISUftjIVV '^Spppppppppppppppppppppl
80 mm. long, has a tenuous neplonic structure of about four
whorl®
with a very small apical angle, and has the anal sinus
on a band behind the peripheral
keel,
However, on the earli-
est spire whorls the rib carrying traces of the anal sinus
is on the center of the whorl, with a subequal rib before
and after: thus the elements of sculpture are tricarinate,
with the central rib carrying the anal sinus. On the adult
whorl the anterior primary rib has become stronger than the
central rib, and forms the peripheral keel.
In the writer's opinion, the genus Turris s.l. Includes those gastropods that have neplonic whorls in which
the anal sinus lies on a central rib or keel, the only sculpnuclear whorls of Polystira
and
ture is spiral (exceptions;
-«
*MMmmmmw
■**
j
first spire whorls of gesmmla )
;
mmm*<m*<.>
mmaim,***miTj-
, the canal is elongate and
simple, the anal sinus is deep and on the median rib, and
the interior of the body whorl is Urate or fluted (except
*a
%" npbills
Hinds, whore fluting Is present only adjacent
to the outer lip).
The subgenus Turris s.s. is distinctive for its
198
smoothly sculptured shell and pre-eentral peripheral keel.
Subgenus polystlra Woodring. 1928
Type (by original designation), Pleurotoma albida
Perry, Hecent, fest
Indies and Florida.
Polystira is easily distinguished from the other
subgenera of Turris by its prominent two-flanged keel, its
heavy shell material, the rather wide columella bordered
by thin callus, and the prominent growth-line traces.
The
presence of axial ribs on the nucleus Is also distinctive.
Turris (Polystlra) albida (Perry), sensu lato
The synonymy of this widespread and variable species
may be found in Oinomikado, 1939, p, 624., and in Anderson,
1929, p. 113.
The specimens here recorded belong to the group previouslyw known
Perry." The iscuadorean
as "Pleurotoma mmmmm
albida
m»m
■.mwwmmm<mmm\*r ■ m\*w\t\»m*«mim»m
w
n,ininiru.i
nn
specimens compare closely with the figure of
alblda
haltensls" in Usury, 1917, pl. 34, fig. 4, from Santo
Des&ißgo.
They differ from the relatively well-defined Tur-
ris (Polystlra) barrettl (Guppy) from the Gatun formation
of Panama:
T. barrettl Is larger, has one strongly doml-
nant peripheral keel, and is finely fluted on the Interior
of the body whorl, whereas the
present species
is of moder-
ate size, its peripheral keel is only slightly more promi-
nent than adjacent keels,
and the
interior of the body whorl
is marked by six strong lirations.
The earliest whorls
seen, about the third and fourth, have the two strong,
199
sharp spiral carinas characteristic of the adult whorls,
one located just before the posterior suture and the other,
which carries the anal sinus, on the middle of the whorl.
The figured specimen is the largest of 8 specimens from
locality I.P.C* 2558,
Dimensions: length (nucleus and
about three spire whorls missing) 29.4 mm., greatest dia-
«t.r (outer Up iaeompUt.) 9.7 n.
T. albida occurs in the Subibaja formation, Lower
Miocene, of the Las Masas sector and the Zacachun section.
Material: hypotype
no,
20482, Paleontological Re-
search Institution, from locality I.P.C. 2558, Las liasas
sector, Progreso Basin, southwestern Ecuador.
Further
material from locality 11203 in the Las Mesas sector, and
from tha Zseaohun corehole, depth 710-720 feet.
aubgenus Gemmula ielnkauf f
.
1876
Type (by subsequent designation, Goaamaan, 1899),
Pleurotpma ge-Bgnata Hinds, Hecent, from either
Lower Califor-
nia or the Indo-Paciflc, probably the latter.
"Shell like that of the typical genus, but with a
beaded ana! fascicle" (Grant and Gale, 1931, p. 50©).
Mo specimens of T. gemma ta are in the Stanford
lection, but examples of Turris ( Geiamula )
col
(Helbling) ,
Recent of China, a nearly identical species, are available*
T. ffranosa has a short nucleus of about two whorls and
earliest sculpture of short, centrally located axial riblets
200
that within one whorl develop Into a raised, pre-oentral
band of subquadrate nodes.
A posterior sutural collar
develops at the end of the first whorl, increases in
strength
on later whorls,
and on the
fourth whorl extends
posteriorly to overlap on the preceding wborl.
The body
whorl has about six strong interior lirations.
The noded
rib carries the anal sinus.
A specimen is figured on
plate 8, figure 13, for comparison with T. yanin^enl' (f.v.).
Turris ( Gemmula ) vaningenl (Brown and Pilsbry)
(Plate 8, fig* 1!)
Pleurotoaa (Gommula) vaningenl Brown and Pilsbry, 1912,
Proc. Acad, gal. Scl^'"^Lilaaelphla, vol. 64, p. 305,
vol,
pl. 22, fig* 4. Cossmann, 1913, Jour, Conchy!
61, p* 19, pl. 2, figs. 21, 22.
.,
vaningenl (Brown and Pilsbry), Olnomikado,
Turris (Gemmula)
*
mmmm .
mm
Jour,
1939,
Geol. Soc* Japan, vol. 46, no. 555, p. 624,
pl. 29, fig. 14,
*imimm*<mm*mmm*mmm*'
Vmwiwwihiw.ww
mm*'m*^m^m*^<.«mmhmmimtwm*m l
mm «-*
The figures and description given by
quately portray the species.
cossmann
**.***_*
ade-
The specimens from the Subi-
baja formation are apparently identical in all preserved
The figured specimen from
features with published figures*
locality I.P.C. 11203 lacks the nucleus and part of the
terior canal.
strong
The Interior of the body whorl has four
lirations.
Of the Recent forms,
ling)
an-
Turris
(Gemmula) granosa (Helb-
from the seas of China and Japan is very similar to
mmm*mmmmmmmm-mmmmmmm*m*mmmm*mmmmm*m*mmm*mmmmm*mm*m.mm-mmmmmmm^
mm*m mm mmmmmm **» «n* mm mmmm-am mm
1 Murex (Fusus) granosus Helbling, G.S. , 1779, Abh. Privatges. Bona, IV, p. 116 (fide Sherborn, 1902)*
******
****** ******
******
**********************
**
**
«■»
mm
mmmum-mm
mmm.**
mmm>
mm m* m*
m, m>m. **-m*mm***m*mm.*m-imm-m.*m'****mm
201
vaningenl*
Z*
T. granosa is larger, has a stronger pos-
terior sutural collar and carries more sculpture, both
spiral and axial.
The interior lirations of T* granosa
number six in place of the four of T. vanlngenl--a reflection of the more numerous spiral bands.
A specimen of the
I
Recent species is figured for comparison (Plate 8, fig. 13).
**************
Hypotype no. 7987, Stanford Unlv. Paleo. type coll.
*
mi.-**
mum-** mtm. ****■** **^^**mim.m.m.m,m.mmmmtmm*m.m.*.m,m*.mmtmimm.m.mm.mmm.*mm.m.mi***mm.m»*mmm
mummmm*
"Jpplystirs" panamensia Olsson (1942, p. 50, pl. 12,
fig, 4) from the Pliocene of Panama and Costa Rica appears
to be related to T. vaningenl and T. granosa.
It has the
same aperturelcharacters and sculpture except for the pos-
terior sutural collar, which is very low. It probably
should be assigned to Gemmula rather than to Polystlra,
with a noded
since 'Gexnmuia is based on a turrid species
■
'in
in pub
imp ■>
peripheral band.
Turris ( Gemmula ) kalparaensls Marshall and T. laws!
(Powell) of the Mew Zealand Lower Miocene are very similar
*
Q
1*
vsningeal : according to figures by Marshall and Powell,
they differ from T. vaningenl only in fine details of sculp-
wure.
The Bcuadorean specimens of T, vaningenl come from
the Subibaja formation, Lower Miocene, of the Las Masas
sector of the Progreso Basin, where they are associated
with Conus masasen sis, Megasuroula guayasensls, etc.
enclosing strata
The
are slltstone and very fine silty sandstone.
202
Material: hypotype no. 20483, Paleontologies! Research Institution, from locality I.P.C. 11203, near Las
feasas, Progreso Basin.
One additional specimen from the
same sector, locality I.P.C. 2558,
Subfamily Turriculinae
Genus Turriculan scbumacher,* 1817
m«< *ii*wip*i*iiuy jUiwmni.i
Type (by
w
t m *ft*?ex
m
mmmimmmmmo
monotypy),
*
Turricula
flamaeam Schumacher
* -mmm mmmwm
m
m# m
t
m*mm*m*..*mmw'i>m** m
wm^*mmwm*»*n
mi.
tornatua Dillwyn), Hecent, Indo-Pacific.
Turricula Is distinguished principally by having
the anal sinus on a ramp behind the periphery.
The geno-
type, T. tornata (Dillwyn), is without sculpture
whorls.
»orde. end two
Turricu^la
A
on mature
sp.
medium- sized aurrleula occurs in the "Blue silt-
stone*' member of the Daule formation, Middle Miocene.
It-
is marked by unicarinate early whorls, but becomes bicari-
nete on the last three or four whorls.
Material from localities I.P.C. 1080, 1162, 1458,
1461, 1464 in the Pedro Carbo and Jerusalem sectors of the
Daule Basin,
Genus
Type
Fuslj&urrloula Voodring, 1928
(by original designation),
fMiMiM Ball,
35£*ria
( surcula )
Recent, Gulf of Panama.
Fuslturrlcula is notable chiefly for its elongate
nucleus of three whorls and the bicarinate sculpture of
the spire
whorls.
203
Fusiturrieula delgada Marks, sp, nov.
(Plate 8, figs. 4, 7)
Description (based on holotype and ten paratypes):
shell of moderate size, elongate, slender, with elongate
anterior canal,
known.
Nucleus and earliest spire whorls not
Sfire whorls more than six in number*
3arly
whorls with pleural angle of 30 degrees, bicarinate,
slightly
concave between periphery and posterior suture,
ornamented with about six strongly swollen axial ribs
that do not extend to tha posterior suture and carry two
strong spiral cords, and with fine secondary spiral
threads, about three below the carina with the central
strongest, three between the peripheral cords, and two
above the carina, and with a fine anterior and stronger
posterior sutural collar.
Penultimate whorl ornamented
similarly, but lith more numerous secondary spiral threads.
Body whorl with about
seven axial ribs that become weak
and Irregular toward the outer lip, and about 17 fairly
strong secondary spiral cords between periphery and
an-
terior extremity; between the secondary spirals are one
or three tertiary
threads; the spiral pattern
is crossed
by regular growth- line traces, producing a Ficus-like
sculpture pattern.
Aperture narrow, sub-ovate, inclined
at about 15 degrees to axis of shell.
Columella elongate,
simple, barely curved, not calloused.
Outer lip (judged
by growth traces) with deep
anal notch between periphery
204
and suture, strongly antecurrent below periphery, curved
in close to columella at top of anterior canal.
notch deep , slit-like.
Anal
Anterior canal elongate, about one-
half length of body whorl, with shallow anterior notch.
Columellar fascicle barely perceptible.
Variations noted
in strength of secondary spirals and axial ribs on body
whorl among various specimens.
length (Incomplete) SG.O
guslturrlcula
Dimensions of holotype:
mm. , diameter (incomplete)
delgada Is closely similar to F. fusi-
,
nella (Dal! J 1 Recent, type of the genus.
Bull, flus, Comp,
9.omm,
The two species
zool* Harvard, vol* 43, no. 6, p. 261,
pl. 14, fig. 7 (1908).
have in common the bicarinate aspect of early spire whorls,
the sutural collar, and the elongate anterior canal.
The
new species differs from y. fusinella chiefly In having
six axial ribs, not ten, on the penultimate whorl, lacking
tha columellar callus (perhaps because of corrosion), and
having a deeper anal notch.
The new species also resembles
Fuslturrloula lole t'oodring of the Bowden Miocene, having
the same proportions, and differing only In details of the
sculpture, notably the axial ribs of latter whorls.
Fusl-
-1
turricula hmneroaa (Gabb) from the Miocene of Santo Domingo
1 cf. Pilsbry, :i.a., Proc* Acad. Hat. Sol. Philadelphia,
vol* 73, pp. 317-318, pl. 17, figs, 4, 5 (1922).
***»
****,mKmim
m****m*****m.*m*m****mmm,*mm,*mm.m.m*m*****mm*m**********,m.
Is apparently related to F, delgada , having the seme
205
general characters, but differing chiefly in the axial
Fusiturricula sprlngvaleensls (Mansfield) 1
**********
******************* **
m m tm m.^,,4
1 Mansfield, W.C. , Proc, U.S. Nat. MUs. ,
vol. 66, art.
22, p. 3, pl. 2, fig, 2 (1925); Butsch, R. , Verb.
Natur. Gesel. Basel, fol. 54, p, 168, pl. 7, fig,
4 (1942).
******
****** **************** **
sculpture.
m*m**m*m,****m*m.
**■■*#**
m,
.
m.*m******m. mm.********m.^.****m^
n*
.,^n
)lfm
,m*m
from the Upper Miocene of Trinidad is more distantly re■
lated to F.
del^ada,
thicker columella.
cene of
having weaker axial sculpture and a
Fusiturricula woodringi Olsson, Plio-
Panama and Costa
Hica, is a larger species with
weaker axial ribs and more numerous spiral elements than
F. delgada.
Fusiturricula delgada is known to occur only In the
Lower Miocene Subibaja formation of the Las Mssas sector,
Progreso Basin,
where it is associated with Turris albida,
Mofasurcula guayasensis, etc,
fine, silty
sandstone,
The enclosing matrix Is a
The trivial name Is from the
Span-
*
ish, meaning "slender,
Materials holotype no. 20484, paratype no. 20485
(figured), and paratypes no. 20406 , Paleontologies! .Research Institution.
Paratypes
no. 7988, Stanford Univ*
Paleo. type coll.| all from locality I.P.C* 877, near Las
Masae, Progreso
Basin.
Genus cruziturricula Marks, gen, nov,
designated):
(Pleurofuala)
Type
(here
*
*
*
Turricula
-'
m
«W
—.—
«P
eruziana Olsson.
u-.i ip.-,,
,^»..
„..i
ii
ii.ni i.up. ■ P.UIII.ipi.hi.
206
Description: shell slender, fusiform, the ratio of
maximum diameter to height about 1:3; aperture narrow,
nearly one-half length of shell.
Nucleus
gate, consisting of about two whorls*
whorls
attenuated,
median
carina,
smooth,
elon-
First five spire
larliest sculpture an undulating
within one turn irregular axial swellings,
nearly round in outline, and a posterior sutural cord de-
velop.
About six axial swellings per whorl on first six
whorls. On later whorls the axial swellings become irregular in shape and spacing, varying from five to eight per
whorl,
A spiral thread developing above the .peripheral
carina on about the fifth whorl gives later whorls a
weakly bicarinate outline*
Adult sculpture of strong,
Irregular axial swellings crossed by the median cord, the
weaker post-median thread, weaker spiral threads, and with
a posterior sutural cord.
Outer lip
Sutures appressed.
with about five short denticles interiorly*
The genus is
most easily recognized by the attenuated early spire whorls,
early aesocostate spire sculpture, and irregular adult axisl
sculpture.
Cruziturricula is most closely related to Fusiturrl■m*m*mmm:<#iim*wwmtm mitmmu
m*mmmms'. m*.wi*mmmmmM-.m**m*#*mmtm**»m*mmm*mmm
cula tfoodrlng, differing ftom it as follows: Cruzlturrlcula
has a more attenuated
nucleus and early spire.
The apical
angle of Cru&lturrieuia is about 20 degrees, while that of
Fusiturricula fusinella (Ball), the type of Fusi turricula ,
207
appears to be over 30 degrees.
Cruziturrl
cula has a meso-
costate (unlcarinate) early spire sculpture, while Fusi-
turricula is bicarinate.
cula has
o ruz.it vrri
irregular
axial ribs, while those of Fusiturricula are regular and
evenly spaced.
The anal notch of Fuslturrioula is deep,
terminating with a vertical angle against the suture.
The
anal notch of Oruziturr l
cula is a deep slot, terminating
with a retrocurrent, oblique line against the suture.
A phylogenetle sequence is apparent in the succes-
aio* "Turriculaw eolavlala Olsson, Lower Socans of
Z* n IiHJL Olsson,
n
Peru,
Upper .loeene of Peru, and cruzi turri-
cula eruzlana (Olsson), Lower Miocene of Peru and Ecuador.
The sequence may continue with "TurriQuia'* andeslta olsson,
Pliocene of Panama and Costa .Rica, but this cannot be ascertained because the nucleus and early whorls are missing on
the figured specimens.
The Becent representatives of the
* lavinia Dal! and
sequence are "Turricula
wj***
arcuata
Ball from the west coast of Mexico and Central imerlca,
which have the attenuated spire, irregular adult axial
sculpture and anal slot of cruziturricula eruzlana, but
differ from it by lacking the earliest of the axial swellspecimen of 0. arcuata (Dall) is figured for
** ******** **** mum
„
#»
«» ** mi m m **** m *********** **"******■*************.**
****mtm.m» m m m
1 Hypotype no. 7638, California Acad. Sci., Dept. Paleo.
"type coll., from locality no. 17943 (C.A.S. ), dredged
in 14 fathoms, sandy mud, off Puerto Culebra, Costa
Rica. Locality information kindly furnished by L.C.
Hertlein of the California Academy of sciences.
ings,
«,*».»
a
.urn*
..
m.^
mum
mmmm
mmmm
m* **.**■**
*mm*mmm*mmm*-m!^*m^^^&m*mtmmm*m»~*
208
comparison (Plate 8, fig* 5).
"Drillla* fuainus Browi and Pilsbry, wfcioh ranges
through the Gatun formation of ranaoa, has a spire that
is more attenuated than that of g^il^XT.lc.u!a. I^ainella
,
(Dall), the type of Fusiturricula but less attenuated
than that of Cruziturricula.
that of £,
The early sculpture is like
crnzlana, but by the fifth whorl the secondary
thread on the periphery becomes almost as strong as the
primary, giving a bicarinate appearance to the whorl. The
adult axial sculpture Is irregular.
The species Is Inter-
mediate between C. eruzlana Olsson and Fu^yurr^ieula iole
-oodring.
It Is probably best placed in Fusiturricula be-
cause of its little attenuated spire and early development
of bicarinate sculpture.
Cruz.iturrIcula eruzlana (olsson)
(Plate 8, fig* 7)
Turricula ("Pleurofaala ) eruzlana olsson, 1932, Bull. imer.
""'Jalso *t vol. "117" '.§* TMlT^pX* 15, figs* 6, 10.
Description (taken from original in Olsson, loc, cit, ?
and amended principally by additional description of nuclear
and early whorl features): shell about 25 mm* In length,
fusiform; nucleus consisting of about two tall, saooth
whorls; apical angle about 20 degrees; earliest sculpture
of an undulating median carina with irregular axial swellings of nearly round outline and a posterior sutural cord
209
developing on the first whorl; about six axial swellings
per sharl on first six whorls; adult sculpture of a strong
peripheral spiral cord, a weaker post-peripheral cord, a
strong posterior sutural cord, other weak spirals below the
periphery, and weak, irregular axial swellings, about five
to eight in number*
Anal fascicle sculptured with three
weak spiral threads, wide, nearly flat; ana! sinus deep,
lying in the anal fascicle. Dimensions of hypotype no*
20487? length 23.4 mm., maximum diameter 7.5 mm., length
of aperture 11*0 mm,
CruziAs mentioned in the description of the genus mmmmmmmmmmm
turricula, 0. eruzlana is preceded stratigraphically by
piura (Olsson) and C. eolaylnja (Olsson) fro®
of Bern.
c.
the Eocene
It may be the ancestor of "Turricula** anneal ta
Olsson, Pliocene of Costa Bica and Panama, and is represented la the .Recent fauna by Cruziturricula lavlala (Ball)
am^
£" arcuata
(Ball).
Material? hypotype no, 20487, Paleontologies! Research institution, from the Zacachun corehole, 130-140
feet, Progreso Basin, Ecuador*
same corehole, depth 140-150
a second specimen from the
feet,
stratigraphlc position
72-90 feet below the top of the Subibaja formation, Lower
Miocene*
Miocene
Examples of the species also occur in the basal
Angostura
formation of northern Seuador.
210
Subfamily Conorbilnae
Genus Megasuroula Casey, 1904
Type (by subsequent designation, Grant and Gale :
1931, p. 495), Pleurotoma (Surcula)
Hecent, west coast of
carpenterlana Gabb,
North .America.
Megasureuls carpenter lana has a nucleus of two
broad, bare whorls.
The earliest sculpture consists of
a half-whorl of basal nodular swellings.
For another half-
whorl the basal swellings lengthen axlally and ere crossed
by two basal spiral threads or carinas, and a low posterior
sutural cord develops.
The «horl profile is concave, with
the base strongly swollen by the axial swellings and the
spiral carinae.
On later
whorls numerous subsqual spiral
threads develop, the basal nodes disappear and are replaced by clear growth-line traces, the basal carinae re-
solve into a basal swelling, the posterior cord shrinks
to a barely discernible swelling, and the whorl profiles
remain concave.
On some adult whorls, nodes or
tubercles
develop on the angulation, which is just before the middle
of the whorl.
Megaeureula differs from Turrleula tornatua.
.
(Dillwyn), the type of Turrleula
chiefly by having the
strong spiral elements of the early sculpture, by having
a shallow anal notch, not a deep slot, and by having the
anterior canal relatively poorly defined,
Cllnura Bel-
lardi (synonym; Bekewls Stewart) is very closely related
*°
Magasurcula. it has the same shallow anal sulcus and
211
noded shoulder.
It differs from Megasurcula in its longer,
better defined anterior canal and stronger nodulatlon. It
is believed to be the ancestor of Megasurcula in northern
America, having evolved into the latter genus in Oligocene
or earliest Miocene time.
Megasurcula guayasensls Marks, sp,
nov.
(Plate 9, figs, 1-3)
Description (based on the holotype and four paratypes): shell of moderate size, biconlcal, the body whorl
about 60 per cent of entire length; nucleus not known;
spire of six whorls, pleural angle
50°, whorl
profiles
concave; body whorl concave above periphery, angulated ,
barely convex below, completely sculptured*
sculpture
Earliest
seen (on second spire whorl) consisting of basal
nodular swellings crossed by spiral threads; later sculp-mm* m
ture consisting of basal nodes crossed by two primary
spiral threads, strong spiral threads
over remainder of
whorl, and rather prominent growth-line traces; penultimate
whorl ornamented with 20 anterior nodes that are crossed
by two raised spiral cords, five raised primary spirals
behind the nodes, various intermediate fine
secondary and
tertiary spirals, and rather prominent, closely spaced,
symmetrically curved growth-line traces; back of body
whorl between angulation and slphonal fascicle ornamented
with eight raised primary spiral cords, each pair with a
212
secondary thread and fine tertiary threads, and axial sculp-
ture of irregularly spaced, raised growth-line traces, the
resulting pattern resembling that found on examples of the
genus Ficus.
sutures slightly Impressed.
Aperture
elon-
gate, sub-ovate, the greatest width opposite a point just
below the angulation, the axis forming
angle of
15°
with the axis of tha shell; columella nearly straight, elon-
gate, rather regularly tapering; parietal wall smooth, with
a thin callus; outer lip missing on type specimens, judged
by growth lines to be gently sinuous; anterior canal moder-
ately elongate, poorly defined, with moderately deep notch;
anal notch Judged by growth-lines to be a shallow, summet-
rlcal arc subtended by a central angle of
Radians) between periphery and suture.
100°
(.55 TT
Shell material
rather thick. Dimensions of holotype (imperfect): length
26,2 mm*,
diameter 12.9 mm.
Diameter of paratype no. 20491
(P.P.1. ), the largest specimen, 13.8 mm.
The new species is assigned to the genus Megasurcula
mainly because of its shallow, gently curved anal notch,
poorly defined anterior canal, and its characters of sculpture.
Megasurcula guayasensis is most closely related to
1
M. bowel Hanna and Hertlein from the Temblor formation,
*mm****mm*m**mm<*»immmmmmmmmmmmmmmmmmmmmmmmmmmm
....»* mmmmm^mmmmmmmm
1 Jour. Paleo., vol. 12, no, 1, p. 107, pl. 21, figs. 10,
12, 13 (1938).
."..."""**»*«*
aa «««*p.
v« <**.***«w
a.*.*.*«.*a>«p»*p»<**w»»i.**.«.i»
213
Middle Miocene of California. From U. howel it differs by
being slenderer, smaller, and
more finely noded. In aspects
of general shape, spiral sculpture, columella, aperture,
outer lip and canals the two species are nearly Identical*
1
M. keep! (Arnold)
also from the Miocene of California,
,
mmmm**■**-*.*********mm* <********■!*.****** mm-mmmmmmmmmmmmmmm m-mmm"mm. ************** ****«mm* mmmm
1 Proc. U.S.
Nat*
, vol.
Mus,
(1907),
32, p. 529, pl. 46, fig* 5
is still more coarsely noded, and In that respect suggest
the genus Cllnura.
M. respond ll (Gabb) and M* carpanterlana
(Gabb) are more lightly sculptured, less angulated forms
of Pliocene to Hecent age in California*
U,
guayasensis
,., occurs
mmm
.at^
M^w^
J).i.i<^,*l^.^.iL^^-ri^n,
ww
J^,^i,
in the undivided Lower Miocene
Subibaja formation of the Las Masss soc tor, northeastern
Progreso Basin, where it is associated with Trltiarla lan-
desi , Turris vaningenl , etc*
The enclosing strata are
siltstone and fine, silty sandstone.
The trivial name Is
derived from that of the Province of Guayas, Ecuador,
Material: holotype no, 20488, Paleontological Besearch Institution, from locality I.P.C. 11205, near Las
Basin.
Paratype no, 20459,
locality I.P.C. 11203.
Paratype no, 20490,
Masas, northeastern Progreso
, from
P.H.1. , from
P.H.1.
locality 11205, Paratype
from locality 2558.
Paratype
no. 20491,
P.R.I,
no. 7989, Stanford Dnlv.
Paleo. type coll,, from locality I.P.C. 877, south of Las
.
Masas
214
Genus Clinura
Type
Bellardi, 1875
(by subsequent designation, Bellardi, 1878),
.lurex (Pleurotoma) calliope Brocchi, Miocene, Italy.
Under the synonymy of Clinura must be included
Nekeaia Stewart, 1926, as has been well shown by Grant and
Gale (1931, p. 494) and Beets (leidsche Geol, Med., vol. 13 »
no. 1, 1942, p. 365, pl* 57),
The stratigraphic range of Clinura on the west coast
of Worth America includes only the loeane.
cludes the Miocene and
pliocene.
In Italy It In-
In the Miocene deposits
of California, Clinura is apparently supplanted by
cula.
Megasur-
CHjmra may be distinguished from Megasurcula mainly
by its sharper angulation, more prominent nodes on the
periphery, shorter, stouter columella, and-- stronger spiral
astfeornamentation* The occurrence of a species of Clinura In
'
the Lower Miocene deposits of Ecuador may indicate the
latest period of survival of the genus in the Americas.
Clinura sp.
(Plate 9, figs* 4, 6)
Two specimens, neither with nucleus or anterior ex-
tremity preserved, were found in the Lower Miocene Subibaja formation of the Las Masas district, and three more
in the carrizal sector.
The species compares closely with
(Weaver)
'
' of the State of Washington
C* washlngtonlana
'
PPJI.
<1«,1».P..
J«.i,iW»linTlfflliil.iini
ipiPiii.nupilPiiil in
Eocene, differing from it only
in details of sculpture and
In having the anterior portion of the body whorl slightly
215
less constricted. From
Megasurcula guayaaensl s it differs
in the stronger, fewer nodes, much stronger angulation, and
longer columella; however, the two species are very similar,
S* jguayasensis
C.
sp*
having several Clinura -like characters, and
tending toward Megasurcula. because of its rather full
anterior portion of the body whorl*
Clinura
ep*
has nodes
adjacent to the anterior suture, a concave spire- whorl pro-
file crossed by symmetrically curved lines of
growth
and
abundant fine spiral threads, a strongly angulated shoulder
with about 11 strong nodes on the penultimate whorl, and a
strongly protractive outer lip. Dimensions of -figured specimens? hypotype no. 20492, P.H.1.
, length
(incomplete) 27.7 mm. »
diameter (nearly complete) 19,0 mm. | hypotype no. 20493,
length (incomplete) 20.0
mm., diameter 12.4
mm*
Length of
largest specimen (locality I.P.C. 11204) 35.4 smt.
Material? hypotype no. 20492, Paleontologies! pesearch Institution, from locality I.P.C* 11204, near Las
Masas, northeastern Progreso Basin,
Hypotype no, 20493,
from locality 11091, near Csrrizal, northern Progreso Basin*
additional specimens from localities 11204, 11093, and 11091.
Subfamily Clavlnae
Genus Crass!spira Swainson, 1840
Typa {? by subsequent designation, Herrmannsen, 1847),
Flsurotoma bottae Valenciennes*
Powell has discussed the
problem of the type designation (Bull, Auckland Inst. Mus. »
no. 2, 1942, p. 11).
216
Cras sispiral cf
. Crass!spiral
consors (Guppy)
Three poorly preserved specimens from the subibaja
formation, Lower Miocene, of the Las Masse sector seem to
be comparable with the common Caribbean Miocene species*
The scusdorean species has a columella that is slightly
shorter and more curved, and its spiral sculpture Is less
prominent than those shown in illustrations of "Fleurdtoma"
„,..,
»i p«.i
in.I,i
in,
».. i^.ii.»,„...
consors*
Material from localities
I.P.C,
877 and 2558 in the
Las Hasas sector, Progreso Basin, southwestern Ecuador*
.
Compsodrlllla Woodring,
*"* * -1921
Genus *f*mmm^^mm^^m^^m^m»mmmim.t
viuin .|i.i.
ipiii./ii«MW;-
Type (by original designation), C, uroeola Woocfrlng,
Miocene, Jamaica.
According to foodring (1928, p. 156), Coapsodrillla
comprises "...the small slender
sculpture,
Drllllas f with Tusus*- like
f
*
'
Compsodrlllla &p.
The specimen from Ecuador is 10.7
mm*
high with the
anterior canal and aperture! features missing,
Indicate a moderately shallow anal notch.
constituted of
strong
Growth-lines
The sculpture is
swollen axial ribs crossed on the
lower half of the whorl by three strong spiral cords.
Material: ono specimen from the Zacachun corehole,
depth 80-90 feet, 32 feet below the top of the Subibaja
formation, Lower Miocene.
217
Genus clathrodrlllia Dall, 1918
Type (by original designation), Pleurotoma gibbosa
Reeve (*
Pleurotoma
mmmm *<mmtmmmmmm*iiwmi*m»Mtnmi
mmnmmr-a
gibbosa
*3Tmm**mmmimmiAi ,**«***"**
Kiener), Recent,* Indian ocean
.
5
plathrqdrillla sp.
This species has the strongly embayed growth-line
of the turrlds.
On the specimen at hand the outer lip
lost, the canal is short and has a siphonal fasclole.
is
The
suture Is collared; the earliest sculpture of heavy pearshaped axial ribs, the adult sculpture of heavy axials,
about 11 per whorl, crossed by wide, rounded spirals, 6 per
whorl below the sutural collar*
anal sulcus.
The axial ribs cross the
Length of the larger of two specimens (nucleus
and anterior canal missing), 12 mm.
ClathroThe Kouadorsan species closely resembles mmmmmmimmmmmmmimmm
'm
drlllla paziana Dall (Proc. U.S. Mat. Mus. vol, 56, p. 14,
pi. 5, fig, 1) of which Dall says, "Though small, this is
a typical Clathrodrlllia,n (Loc, cit.)
cant
The only signifi-
difference between the two appears to be that the
icuadorean specimen has a heavier apertural callus. In the
apertural features it may
come closer to flaeocyma lanthe
Dall (op. cit*, p. 9, pl. 4, fig, 6). Reeve's figure of
Pleurotoma gibbosa ( Pleurotoaa , pl. 5, fig. 30)
,
the type
of Clathrodrlllia Dall (1918) seems reasonably close to C.
paziana Dall, although the axial ribs of gibbosa are somewhat less continuous.
Material: two fragmentary specimens from the zacachun
218
corehole, depth 140-150 feet, 72 feet below the top of the
Subibaja formation, Lower Miocene.
Subfamily Mangeliinae
Genus Olyghostona Gabb, 1872
Type (by monotypy), mmm0* dentiferum Gebb,* Miocene,*
■*"
mmm**
»*r
mm"mmm**.mmtmmmwmn,im*m<M#"m»*<*mtm
Santo Domingo*
Glypho stoma sp*
(Plate 9, fig. 8)
A single specimen was found at locality I.P.C. 1461
In the "Blue siltstone" member of the Daule formation, Middle Miocene.
Material: hypotype no. 80494, Fsleontological Hesearch Institution,
Family Conidae
Genus Conus
Llnn^", 1758
Type (by subsequent designation, Children, 1823),
Conns marmoratts
Llnn^.
In 1810, Montfort (p. 407) cited C. fulguraaa f/ontfort (« C. generalIs Gmella) as the type of Conus.
C. gen~
eralis is not in the original list of species of Conus, and
hence cannot be accepted as type.
Subgenus Dendroc onus Swainson, 1840
, 1847),
Type (by subsequent designation, Hermannsen
Conus betullnus
Linne',
Recent, Indo-Pacif ic.
"Shell medium- sizsd or large, shoulder
rounded and bulging, spire low. siphons!
219
notch wide and relatively deep. Siphons!
fasciole correspondingly wide and slightly
bulging. Anal notch very shallow, anal fasciole flat. Sculpture consisting of low
threads of irregular width on base of shell.
Uoodring, 1928, p. 202.)
Conus (pendroconus)
"
brsvol Spieker
Melson, 1870, Trans. Connecticut Acad,
Sci,, vol. 2, p. 194 (fide Olsson, 1932, p. 151)*
Co nus sp. md. C.
Conns molls
Studies
var. bravol Spieker, 1922, Johns Hopkins Unlv. ,
in
GeoT77"no.
3, p. 41, pl. 1, fig. 6.
Conus (gandro conus) brsvol Spieker, Olsson, 1932, Bull*
A&er,
?ai'ebT7~vorr~ls? p. 151, pl. 16, figs. 1,3,4.
The flat spire whorls, very faint spiral sculpture
on the spire, and the lack of spiral sculpture on the upper
part of the body whorl distinguish this species,
The ratio
of length to diameter is about 1.5: 1, whereas in C. molls
It is 1.7. 1*
In Peru the species occurs In the 2orrltos foriaation,
Lower Miocene, and in the Cardalitos formation, Middle Miocene,
In Ecuador it is .known to occur la the "line silt-
etone* member of the Baule formation, Kiddle Miocene, near
the village of Jerusalem, localities I.P.C. 1456 and 1464.
Conus (Pendroconus) cf , C.
**
bravol Spieker
mmm
mmmmmmmmmmmmmmmmm
mm*m..,m**mmmmmmm
m mmfmumtmrnrnw mrimm..
mum,
nwiiniw*
A single specimen from the base of the Progreso for-
mation south of Zacachun is similar In size and shape to C.
bravo!, but differs from it in having more strongly ante-
current growth-lines on the back of the body whorl.
This
may be a gerontic feature, since the specimen is larger
220
than typical G* brsvol.
The spire is so worn that no
spiral sculpture is present.
Growth-lines on the spire
whorls are only moderately concave.
Diameter of specimen,
Hm .;.■:. I
■
34.6 mm.
\yy-y>-
..
laterla!: one specimen from locality I.P.C, 7618,
Bear
z....1»_,
Program,
Basin.
Subgenus Lapto conus swainson, 1840
Type (by subsequent designation, Herrmannsen, 1847),
Conus amadls Martini, Recent, Indo-Paeifle.
**Shell reaching a large size, spire moderately high, shoulder truncated. Aperture distinctly widened at base, siphonal notch virtually absent. Siphonal fasciole wide, bulging*
Outer lip strongly retractive as it approaches
anal notch , which is very deep, Anal fascioleconcave, bearing obscure spiral threads, sculpture for type species) consisting
* of obscure
grooves at base of body whorl. 1 (Woodring,
1928, p, 208, )
Conus (Lapto conus)
sophus
Olsson
Conus (Leptooonus) sophus olsson, 1952, Bull* Am®t*
vol. it] p7 '1847" pl* la, figs. 6, 8, 9*
0. sophus
***
iinijWimil.mi mm
,i, tn
Paleo.,
occurs In the Lower Zorritos formation
(Lower Miocene) In Peru (loc, cit.).
is found In the basal beds of the
In Ecuador the species
Progreso
formation and in
the **Blue siltstone" member of the Daule formation, Middle
Miocene.
c.
sophus apparently preferred a sand-laden,
brseklsh-water habitat such as that represented by the .Progreso and Daule formations, and did not thrive in the muds
laid down during deposition of the Subibaja formation
(Lower Miocene),
221
Material: specimens from tiie Zacachun corehole,
depth 35-45 feet (basal progreso formation), and from
localities i.r.C. 1461, 1462, and 1464 (Daule formation)
in the Jerusalem sector of the Daule Basin.
Conus (Lep to conus) aff. C. (L. ) sophus Olsson
Ispecies closely related to C. sj^nohus occurs In
the lower Xaeachun member of the subibaja formation (Lower
Miocene).
It has the elongate nucleus, smooth spire shoul-
ders, and general shape of C* sophus
, but; has
faint, raised
spiral bands on tha upper part of the body whorl in addi-
tion to the strong basal spirals present on 0. sophus.
In
appearance it is intermediate between C. sophus and C.
masssen sis (q,v, ),
16
mm*
Tb© largest specimen would be about
long If complete.
Material: five specimens from corehole Bos Bocas
no. ls depth 80-90 feet, Sacachun sector (Progreso Basin),
Guayas
Province,
gcuador.
Conus (Leptoconus)
multi.liratus BCse
Conus agasslzi Dall, var. multiliratus BOse, 1906, Inst,
Geo!.'" Fexleo,
vol,
jcusdoreaa
£"
22
"Q , figs. 34-38.
M
specimens are smaller than typical
the largest (locality
only about 16 mm. long.
.C* 1227) being
They lack the strong axial lines
of the variety C. multiliratus
gaza, which Is also smaller
than typical C. multiliratus.
The species and varieties
222
of it are apparently wide-spread in tropical American
Mio-
In Pieuador, numerous examples were found
cene deposits.
in the "Blue siltstone** member of the Daule formation,
Middle Miocene.
Material; specimens from
localities I.P.C. 1162,
1227, 1457, and 1464, Daule Basin , leuador.
Conus (tsntoconus) masssensls Marks, sp. nov,
(Plate 8, figs. 9, 10)
Description of the species (based on holotype and
three paratypes): shell small, biconic, spire about one-
fourth of height; nucleus elongate, of about three whorls
with apical angle of 28 degrees; spire of six concave, un-
adorned, turreted whorls, with pleural angle of about 80°;
body whorl ornamented on upper half by rows of small nodes
arranged perfectly In spiral lines and crudely along growth
lines, on lower half by about 12 flat-topped, raised bands
slightly wider than their interspaces; shoulder of body
whorl obscurely tubereulate; siphonal notch moderately deep
outer lip strongly retractive; anal notch deep; anal fas-
ciole concave.
fro®
75 to 85
Variations in pleural angle, which ranges
degrees;
in nodes of body whorl, which may be
Isolated or on raised bands; in number of bands of nodes,
which ranges from five to seven.
length 16.5 mm., diameter 8,3
mm.
Dimensions of holotype:
The largest of four
specimens from the type locality, paratype no* 20496, has
a diameter of B*7 mm.
The most characteristic features of
223
£" masasensis are
the noded. upper half of the body whorl
with the accompanying obscurely tuberculate shoulder on
the body whorl only, and the elongate nucleus*
is placed in Lentoconus
Conus masaeonsis
because
.
maun,
»-M**.ii.iw.i.pi.pimwMi.Mi
;mmmtin
in.nin*wii|i<l|in i m.iih.. .nm irtjB>^.ii.i.- :rttnHWf
iii.iiw.Mw*ii*wi..iMi.Miiini>ii^iili»
of Its strongly retractive outer lip, deep anal notch, and
shallow slphonal notch. It is related to both the Conus
(Leotoconus)
multiliratus B<3se group and to Conus ( Lepto-
conus ) soohus olsson. Members of the species 0. multi-
liratus differ from £.
masasensis in being broader and
having a shorter nucleus.
The subspecies C* multiliratus
spiekerl
Olsson from tha Lower Miocene Lower Zorritos for'p.
mJBI
i.
ii
hi ■■
iti.Pi
mation of northwestern Peru is noded like C. masasensis,
but differs from C.
nodes as
masasensis In the character of the
well as In shape and nucleus*
C. soghus from the
Lower xorritos formation of Peru is not noded, but in all
other respects, Including size and character of nucleus,
closely resembles C. masssen sis.
"**at,
A common ancestry may
Conus berry! Spieker from the Lower Zorritos for-
mation of Peru is somewhat similar to C* masasensis in
mm*
mmimtiimmm^
>^im>,nzmm><"<^.mitiH>nlt\mm
general appearance and size; however, it is not noded on
the body whorl, and bears tubercles on the latter spire
whorl shoulders.
Conus (Leptoconus) imitator llus tfood-
ring of the Bowden Miocene is also
similar
to C. masaaen-
sis, but lacks the nodes and is larger.
* masasensis
Conus (Leptoconus)
*mi
»—!■«».«■
mm ii*wii
wyimPlillliiiiii ii
****mmi>mmnmmzmmmm,
immmmmmk inmimmmt
nmmMWtmmm*'mm,i>mim
occurs in the Lower
224
Miocene Subibaja formation in the northeastern part of
the Progreso Basin,
The detailed stratigraphy of this
sector has not been worked out, and Its position within
the formation is not known.
Associated with C. masasensis is a large assemblage of moHusks including Conus (Laptoconus) roigi,
Muculana, (Adrana)
' etc.
* sp„
"* ' Batlea sp, ,
n
■in..i
1,,
.vi ii
i
i
in ■
mi
.niiiininiirii
unirinnpjn ■
i
n ii.kii.i
'*-
The enclosing
**
strata are siltstone or fine silty sandstone.
The trivial
name masasensis is taken from the village of Las lifesas,
which is close to outcrops from which the type specimens
were taken.
Type material: holotype
no. 20495, Paleontological
Research Institution, from locality I.P.C. 2558, 3.0 km.
N
S6°
f of the village of Las mass, Guayas Province,
Ecuador.
Ity.
Paratype
.no. 20496 (figured) from the same local
Paratypes no,
7990 (two specimens) in the Stanford
Only* paleo coll, from the
same locality.
Conus (Leotoconus) rolgl Marks, sp. Nov.
(Plate 9, figs, 7, 9)
Description (based on holotype and three paratypes):
shell of moderate size, bieonlesl, spire about one-third
of total length; nucleus of three elongate, bare whorls
with apical angle of 45 degrees; spire of seven whorls,
with pleural angle ranging from 65 degrees In specimen of
six whorls to 90
degrees
in specimen of seven whorls;
225
spire whorls ornamented with prominent tubercles crossed
on the sides by two slightly raised spiral bands; tubercles numbering 21 on penultimate whorl of holotype, bands
extending only to penultimate whorl; growth lines regular,
prominent, moderately recurved on body whorl; body whorl
with sharply angulated shoulder, ornamented on base by
about 14 raised spiral bands of irregular widths; siphonal
notch rather shallow; anal notch deep; anal fasciole con-
cave. Dimensions of holotype (Incomplete): length 27.6
diameter 15.2 mm*
C,
mm*.
roigl is distinguished mainly by the
banded tubercles on the spire whorls.
Conus roigi Is placed in Ley_toconus because of the
deep anal notch, shallow siphonal notch, and sharply angulated shoulder.
Tha outer lips of the types are broken,
but are presumably retractive*
The most similar described
species is C. tuberace la Anderson from the Tuberd group,
Miocene, of Colombia*
C.
roigl is smaller and thinner-
shelled than 0. tuberacola, lacks the beaded sides on the
young specimen, and has sharper spirals about the base of
the body whorl and stronger growth-line traces on the
spire whorls.
C. rpigi was found at two localities in the Subi-
baja formation, Lower Miocene, of the Las Ifesas sector.
Associated with it, in a matrix of fine silty sandstone,
were Turris polystlra sp. , Tritiaria( Antlllophos )landesi
Marks, Turris (Gemmula) vaningenl Brown and i-ilsbry, etc.
226
£*
roigi occurs in the Subibaja formation, Lower
Miocene, of the Las Masss sector of the Progreso Basin.
Associated with it, in a matrix of fine silty sandstone,
ar@
Turris albida, Trltiarla landesi, Turris vaningenl,
The species is named for C. A. Roig, who collected
etc.
most of the type material*
Material: holotype no. 20497, Paleontologies! Research institution, from locality I.P.C. 2558, near Las
Masas,
Paratype
I.P.C* 11203.
type
no. 20498 (figured) from the locality
Paratype no, 7991, Stanford Univ. Paleo,
coll., from locality
1,P.0.
11203, near Las Masae*
Genus stromblconus Marks, gen. Nov.
Type (here
Marks, sp.
Nov.,
designated), strombl conus ecuadorensls
Lower Miocene, Ecuador.
Description (based on two specimens of tha type
species): shell biconlo, moderately large, with sharply
sngulatsd shoulders, narrow, elongate aperture, and shal-
low anterior notch.
Sculpture of fine spiral striae on
spire whorls and base of body whorl.
Mo anal notch.
Parietal wall thinly calloused, outer lip straight posteriorly, slightly antecurrent below shoulder, retrocurrent
toward base, thin-edged, interiorly smooth, unemarglnate,
Anterior notch barely defined, shallow, Siphonal fasciole
moderately raised, sculptured by growth wrinkles, continuing beneath
columellar callus*
227
The general appearance of the type species is that
of a high-spired cone; but the lack of an anal notch, the
sellout outer lip, and the calloused parietal wall are not
characters of tha genua Conus*
The calloused, parietal wall,
bulging siphonal fasciole, nearly straight growth lines on
the whorl shoulders and salient outer lip resemble features
°*
3trombus; but the tubercled angulation and *etrombo!d
notch** of atroabus arc not present on strombleonua*
The
conus Is not known, but there Is no In-
nucleus- of
dication on later whorls of any
strong neplonic
ornamenta-
tion such as occurs on strombus and Clayella. Lmaoozpnla
has a similar spire, siphonal fasciole, and anterior notch,
but its plicated columella and toothed
rt
etrostbold notch*'
are foreign to atrombi conus,
i1
m...: -.-w»^**ii*iiin„»Mwp.'i'->*"'i»i',ii
<t,mmmn*fi.mmm
atromMconus scua&qrensla Marks, sp. Nov.
(Flats 9, figs* 10, 11)
Description (based on holotype and
one paratype):
shell rather large, bi conic, thick-shelled*
known,
nucleus un-
spire of about five whorls with sharply angulated
shoulders, concave posteriorly, ornamented by fine spiral
striae crossed by growth-lines, with pleural angle of 75
degrees.
Body ti&orl with sharply angulated shoulder, con-
cave posteriorly, ornamented only by growth-lines and fine
spiral striae about base.
thinly calloused.
Mo anal notch.
Parietal wall
Outer lip straight posteriorly,
228
slightly antecurrent below shoulder, retrocurrent anteriorly, most salient at middle, thin-edged, unemargiColumella without folds.
nate.
defined, shallow.
Anterior canal barely
Siphonal fasciole low, terminal, marked
by curved lines of growth, continuing beneath parietal cal
lus. Dimensions of holotype: length (nearly complete)
47,0
mm*,
diameter (nearly complete) 29.6 mm.
Dimensions
of paratype: length (early whorls missing) 44*0 mm. ,
diameter (nearly complete) 30,6 mm*
Ho close relations of this unique shell are recog-
It occurs only in the subibaja formation, Lower
nized.
Miocene of the northern
Cavilucina cf.
Conus,
*iiiwmmmmmmwm
w
c.
Progreso
Basin, associated with
sechura (Olsson), Clinura sp.
, Flous sp. ,
and Turritella conauistadorana Hanna and Israelsky,
w
*mmmmm*mmmmmmmmmmmmmmmmmm
mi'u
iiiiiiMwiii>iiilfli»iiu.»
\mm*mw «.i,iv«ntiMn.iHM.i mwmmmma*
Material: holotype no. 20499, Paleontological Research institution, from locality I.P.C. 11092, 5.4 kilo-
meters H
38° Iof
paratype
no. 20500, from locality 11138, 1.3 kilometers
817
|of
Carrlzal, Guayas Province, Ecuador;
Carrlzal.
229
Class CEPHALOPODA
Subclass TJKTRABRAKCHIATA
Order
Ey^EEE^A
Family Aturidae
Genus Aturla. Bronn, 1930
(by subsequent designation, Herroannsen, 1546,
Type
and by virtual tautonysßy), nautilus
a.turl Basterot. Lower
Miocene, France.
Aturla eurvilinesta- wilier and Thompson
mimi\mmmm<.mmmmmi> ■'.-
tti^w^iw^wiftwiiiHiiMiwiii^
Aturla curvllinesta Miller and Thompson, 1937, Eclogue
geol. Helvetlae, vol. 30, p. 61, 69-70, pl. 0,
figs. 1-4, pl* 10, figs* 1, 2* Miller and Furnish,
1958, Jour. Paleont., vol. 12, p* 150, 151, fig* IG,
Miller, A. X* , 1047, Geol. Soc. Amer. Hem* 25,
, 93-94, pl. 73, figs. 3, 4, pl. 84, figs. 1, 2,
5-8, pl. 85, figs. 4*6.
This species occurs in the Subibaja formation, Lower
Miocene of the Carrlsal sector, northern Progreso Basin,
Ecuador. Four specimens were taken from locality I.P.C.
11114, one of which is figured by Miller, 1947 (pl. 35,
figs. 4*6}*
A fifth specimen, from locality I.P.C. 2408
of the same sector and horizon, measures approximately 7C
mm*
in maximum radius.
The type material described by Killer and Thompson
and by Miller
dad.
cam®
from the Miocene of Venezuela and Trlnl*
Accurate stratlgraphle information on the localities
Is apparently not available.
The Trinidad specimens are
from the Middle? Miocene Srasso formation (Ouaraeara lime-
stone J*
The Cuaracara limestone is now believed to be
lowermost Mddle Miocene (Upper ftuclan Stage of Renz, 1948;.
230
material, hypotype no* 799E, Stanford Univ, Paleo,
type coll., from locality 1.1-.C. 11114, 3,0 kilometers
8
45°
|of
Carrlzal, Cuayas Province,
igcuador
,
(Millar,
op*
cit*, pp. 95-94, pl. 85, figs* 4-6); hypotype no, 20501,
Paleonto logical Research Institution, from locality 11114
cit.,
(Miller,
op*
locality
1.1.C,
pp*
£498,
93, 94); hypotype no. £0503
4,1 kilometers X
(Miller, op* cit., p* 94),
H* S, Landas, 1943.
77°
from
a of Carrlzal
Locality 11114 collected by
Locality 2498 collected by C. Eolg,
1942,
Phylum
If mOfODA
Class CRUSTACEA
SubClass E:CE:.:STACEA
Family Callianassldae
Genus Calllanassa
CalliansssaV sp.
Two dactyli of the left or .minor cheliped of a
rather large hermit-crab were found In the lowermost beds
of the Progreso formation, Kiddle Miocene.
The fragments
are not idcritical with analogous parts of any known species.
alllsnassa vaughanl Rathbun (1918, U.S.K.M. Bull, 103,
pp*
148-150) has the sane general appearance, but its dactylus
Is higher than that of the present species, and it lacks
the distal group of teeth present in the gcuadorean species*
231
Dimensions of larger specimen; length (about 60-,;, complete)
ZZ Ma* 1 height (through proximal group of teeth) 9.3
mm*
Materials two specimens from the ftaeaohun corehole,
depth 55-413 feet, Progreso Basin, Sounder.
PLATES 1-9
232
Explanation of Plate 1
Figures
mi mi
■ iijWp
iih
in—
I*s*
'
formation, Lower Miocene,
4-5.
.
liuoulana laacoella) sublbajana Marks, sp. Nov.,
x2". Tt'"3.TbXo'typa f "2, paratype subibaja
Nuculana (Saccella) salbana Harks, sp* nov.,
ll* ¥7"holotype; §, pa'raiypa. Vppez Oligocene
and lowermost Miocene (Subibaja formation),
Progreso Basin.
.
mp* »w
Buoulaaa (Adrana)
*
W
,
tlon Lower Miocene
WIM.MiMMMi
PP. I
«rrr|Wi«*,
;
...l»)llui
UliUMlttlJlI
m
x I*26*
subibaja
forumw
7-9
Noetia dauleana Marks, sp. Nov., xl. 7, 8, paratype; 9, holotype. Daule formation, Middle Miocene "
10, 11
Marks, sp. gov.,
Anadara (Anadara) alargada
'
xTTfT" Holotype'* subibaja formation, Lower
Miocene,
IS, 13
Noetia smcneili Marks* sp* nov,, x2. Holotype.
Subibaja formation. Lower Miocene.
mi
wwrHlM—.nw
'■.*»,"■
Mi*vii
m<mmmmmmmtmmfmmmmm-
'
i# i
233
Explanation
*: * i
§*
"
Plate
2
Anadara (Cunearca) thalla
(olsson), x 1,3.
'
BauleTorS"tlon, Mi'ddle tolocene,
11
yas%!a
sp., xl,
Mld'eshe*
f* 9
of
l
lJ
subibaja formation, Lower
Ostrea (Lopha) sp*
Middle Miocene.
, x0.83.
Baule formation,
Pecten (Aeouipecten) plurinominis
snsis~~Marks«
Progreso
subsn,
pre.gr®
so-
novTTldSr* Hololyps.
formation, Middle Miocene.
Plate 3
j -'/;
':
-z
234
of
Explanation
Plate
3
Figures
p
iii.hl mini mm«wm.*i**mmmmmm
1
Pecten (Aoquipecten) woodringi Spieker, x 1.2.
Progreso formation, Middle Miocene.
2, 7
Pecten
amenensis Marks, sp. Nov.,
Progreso
l.Eo*
formation, Middle Miocene*
X
3,6,8
Eucrassatella carrizalensis Marks, sp. Nov.
3, 6, holotype, x 0.9; 8, paratype, x 1.1.
Subibaja formation, Lower Miocene.
4, 5
progresoensis
*
Pecten (Aequipecten)
. miplurinominis
9mmmmm***m^mmm&mn.mmmmmmim»iiv
Jm%mmmmmSmm»*Mti^.*iliimti
■n.w m.iww*.**
tm.
wy.■»..*%n nl...w.Tfat.iuii.m'mmi
i
tmm
ww>*wi*i
mmojmm*m ■.■■■n \tm\tmt
Marks, subsp. Nov.
4, holotype, x 1.35; 5,
paratype, x0,9. Progreso formation, Middle
mmotm*mmf
Miocene.
■
j ,, tf
3
235
Explanation of Plate 4
Figure
1.
2,
Luclnoma? sp.
iioceneT
, x2,
Subibaja formation, Lower
Marks, sp.
Pitar (Lamelliconcha) zacachunensis
"
nov,
, x 'I*lB.
HoloiypaV Uppermost subibaja
formation, Lower Miocene.
m>
m*
a*
Sornia (Temblornia)
keenae Marks, sp. Nov.,
"'
'formation, Lower
'"subibaja
Holoiype.
x'°Sr
Miocene.
M
Cay1lucina (Pegophysema) cf, C, (P) sechura
TolssonJVat £V
suMbaJa
Miocene.
5.
6, 7.
S,
9.
formation, Lower
x 1.6. Progreso formation,*
"*" ,
Luclnlaca sp.
w
.
mmtm^mmmmmmm'imkitmMmf^
Middle Mio cene
.
' thompsonl Marks, ep* nov*
Pitar (Lamelliconcha)
„,
m
,
,
6 para type x 15 j 7 , holotype , x 1.35. Basal
Gatun formation, Hepubllc of Panama.
„■....».,■...■.NLifp.
*■.,
..,,
.
.mi
pp»p,.p
.,„,.,i ,,i
ppihi.i
ip.pp
i
iWiiilin Kg,. ,i,ippp.,ih»i.,iipppiipip
»
m*
.
dontla etainforthi Harks, sp. nov,, x I.
o type Progreso ""'formation Middle Miocene
,
'
Cayiluclna ( Pe^jphysaias ) thalmann.l Marks, sp.
nov77"3c'l"» Holotype'". Baule'''fomat lon, Middle
r
Miocene.
Plate 4
236
Explanation of Plate 5
Figure
■aria olasonl Marks, sp, Nov., x 0.93.
a. Progreso formation, Middle Miocene*
z*
Sp??,
(WJj^aUa)
(Dall), x
O.f*
■a
o.
4, 7.
0, ©"
gatunensis multifilosue
PaulefiSslfiSnTMiiil¥**llocene
(Could), x 0*66. Pro*
<fi»f*ft)
Ma!!!!
greso formation,ffifllata
Middle Mocens,
i^.g.|!iooncha )
fl,l|£ ,
sp,, xl. Progreso
forSMoa MllTaHEfoma *
gh|^,gg (Chionopsis l dauleana Marks* so, no*.
x 0.82, Holotype* Daule formation, Middle
Miocene*
■
SUM.
aov., (I^JgaUAagnaha)
aaoaelmnensla Sarks, sp.
upper-
most subibaja formation, Lower Miocene*
.
be 5
237
Explanation of Plate 6
Figure
,
4.
Jm.*JL *
.
.
Turritella infracarinata Grzybowski. 1, hypotypiTP.'H.I &b'4sl, x X"."is Daule formation,
Middle Aliocone.
S, 6 *
Architectonica (Architectonica) . sexllnearls
, x I.W, TioXotype.
Hu'llH°^ii¥s7 suispr'noT.
,
Daule Tormation Middle Miocene.
o, a.
(H, ) canrena »antl(Hat i
carius)' cf
Katies
,
„, * I. .mm
—» formation,*"
nacca Cossmann,* x E.5, subibaja
i.,„„..„.^ii..ii.mi
gipn
p»i.
'iimiii
-]-
■
pi-
mmm—
i
■"*>igLi.*mm.im■nmuiv
mm*
ippmi
ii»juii)iiiiii'.iii-
Lower Miocene.
5*
Turritella gatunensis Conrad,
7-9*
Hat lea (Natlca) ep*
formation," ilMle Miocene*
t.R.'fr 2^1417"x
Q?* P-
t
xl,
-.
Marks, subsp,
Turritella
hubbardl
masasensis
, ..
..
■■
,
ja
nov*
x Z* Ho lotypeV Subiba formation,
Lower Miocene*
i.ii.ili
%
.
(d*orbigay)
co^uimben.sls
",
ormafio ii MHlIeTITocane
10,
&,& *
Progreso
7, 9, x 2,5. 8, hypotype
subibaja formation, Lower
E,
Miocene.
11,
x4,
mi.
ii.ii.ii
i,
.»_>!,—
i
pp..p,,..p.,..p.al ..,i
p.,.......-
■.iiriLi..-i.ii in. imiHiii ,m
111 mull
Turritella infracarinata subsp* , x3.
SublSsTja "formation, Lower Miocene,
'
Turritella conqulstadorana
Hanna and mIsraelsky,
mm*i*^«f^.immmmmmmm^mmt
ja
formation,
x 1,£5,
Lower Miocene*
Bubiba
,
mmmmf'^mmmmms^^^^'^'■*''■mutmi ■*^mm
\m**mmmtommm
mm
238
Explanation of Plate 7
figure
"*«
"
Strombina pequenlta Marks , sp. Nov., x3. Holoupper subibaja formation, Lower Miocene.
Type"*
*w**
Phos cf , P.
HE
Architectonica aff* A* nobilis Hading, x 1.1.
Subiba ja formation, To wer^Mlocana*
4♥
tuberasnal.s
Anderson,
Subibaja TorStlon, t'iower Miocene,
x 1.3*
Strombina
cimarroma. Marks, sp. nov*, x3*
''""'' '
type* Subiba ja formation, Lower Miocene,
Holo-
sp. nov,,
itramblna mmmm^wt,mmmm^mmmiomm^!mmmm»
daulechiea Marks,
- * x 4*5.
a
,
olotype* Da ule formation Middle Miocene.
tmmm^mmmymmmmmfmmmm
6.
■
_.
■*;»**»
m
Anachls (Oostoanaohis) Stevenson! Marks, sp.
, x3. Bolofype, subibaja formation,
Miocene.
Nov.
Ijower
7*
sj
Strombina strlataeeetata Marks, sp, nov., x 2.1.
Dauleformat ion Middle Miocene.
*mmm*i*.m<mmm-mi*m wyfv**********
Holotype*
,JLvr ,X JL , cantharus
m>m**^<-,mmmt^m*&mm-,mMi»)^mm. *mr>m-^amamimm
,
■
m*
*t,_JI
iTrlumnhls) predistortus Harks, Bp*
no?* S7"psrstype P.H.IT^IMWT^^O.t; 10, paratype P.B.X* £0475, x 0,9, 11, holotype, x 1.1.
Phos naught! Marks, sp* nov,, x 1,05. Holotype.
baule formation, Middle Miocene.
$M*10,
tie sp. , x 1.45. Baule formation. Middle
ens*
14.
Sconsla sp.
Mocena "
,x
1.35.
Subibaja formation, Lower
Flats 7
239
Explanation of Plate 8
figure
1,
2
Trltiarla (Antlllophos) landesi Marks, sp.
x2. Holotype.
sutibaje foraailon,
Nov.,
Urn
Miocene.
a, »
,)
Trltiarla (jntillo
3*
.
formation, Lower
sp.
,x
S.S, subibaja
ta
Marks, sp. Nov. 4, paraFusiturricula
■ypa, x 2;
otypc, x 1.5* Subibaja formation, Lower Miocene.
...
.
.
5.
(Dall),
' * x 1.25,
Cruzi turrleula arcuata
urn
west coast of Costa Rica
6,
*
* x 2. UpperCruziturricula eruzlana (Olsson),
most Subibaja formation, Lower Miocene.
-ii, i.p 1P..H.1P1.1 ■
,„,ii.pii
in
mpiii
urn.I.i ini-i
,>iwiiirM*ijii*iMimiiiwi^
p..,,
ii
« ■>ip,i
»
10,
Peeent,*
m> <m
mmmmm\mmm*mmwmm**m
Polystlra albida (Perry), x 1,45.
formation, Lower Miocene,
o.
9,
in. ii.ipp
Subibaja
Conus (Laptooonus) masasensis Marks, sp. nov. 9,
paratype, x £.&; 10, holotype, xZ. Subibaja
formation, Lower Miocene.
11.
(Brown
and Pilsbry),
(Oommula)
'
" vaningenl
*
Turris
m
nw
urn.
m«
x 2.1. Subibaja formation, lower Miocene.
Id*
Marks, sp. Nov., x 1. Holo
'
¥.1 tularla ecuadorana
"iype* Dauie' forma tlon, Middle Miocene,
13.
Turris (Gemmula)
in iiijpjjimi
i-
ui».hpii|»i»ppiiiiiipp»..pi.i nippji
ecent, China.
i»wi
nijnvur i
granosa
P P
(Helbling), x 1.28.
W'U&m
240
Explanation of Plate 9
Figure
I—3*
4-5,
jjsgfsureula
17
■
10,11*
nov,, x 2*
glianra sp, 4, hypotype P.8.1. 50491, x 1,5,
ITiThypotype 20493; fig. 5, x S.S; fig* 6,
x 8.05*
7, 9,
.
guayaasasla Harks, sp*
3, holotype; Z* paratype
Subibaja formation, Lower Miocene,
(Leptoconus) roigl i&rks,
gonaa
paraty^TTX*s
sp. Nov.
;
9,
holotype,"»
x 1,7,
Subibaja formation, Lower Miocene,
sp.*,
x g.
formation, Middle
Baul®
atroabiconus acuadorensis
- m
nov.,
:arks,* sp*
x I.E.
**-^
wm . mm
»..-.-«
mmm
~ubibaja 1orma xlda7 Lower t-locena*
?
■»gwa«jijg|ipp<iiiiiiii»ii,iiiiMi iiirj|irm(ini.i
■
--,— »««p
1
*mm-
241
Bibliography
Anderson, F. la,
is marine Miocene of Morth Colombia,
, Sal*., rroc M ser* 4, vol. IC, no.
oalJfor I
3, pp, 87-95, pis. E-3, 1927.
_„ **&arine Mlose
related dapoalta of Bortb
}
,
lJ
IbitL
vol.
18,
no* 4, pp* 78-BIS, pis,
9° V aarch,
''>7 lv£9.
B— s3,
>
Sosworth, i\ o. "Geoloay of t
I*
i in the nc;
, J, -;^ #
j C 0© * , j
-. I ;ary ai
[email protected]
osdllan
irons, A* F. "
I*, A* Pilsbry.
forxiation, Isthmus o;
_
i
Panama
-ia, froe»
1ci i
--aa~j,ofs
f
of the llatun
&* mt* Dei,
vol* mt - pp. 336-574, pl.
the Gatun fox -lion. Isthmus of
ibid., vol* 64, pp. 50C-519, pl
'
. g so parativa de fo.sailes nloCossmasn, a.
c^nigues rar illlls a la artinioue et a l'lsthas
de Panama,** Jour. Jcnchyl. , ser, 4, vol. 61, pp.
1-64, pl* 1-5, 12X8,
»
"
'
Cushman, J. k*
a;-
. ■..-.. -?u
B»
Locene foi
from louador, 11 "- t.shman I I-.
-an.
Contrib, vol, %%* ft* 3, ppm
lnlfsral fauns
lUm**
9-10,
I^4;
,
,
* "Mm "Contributions to the Tertiary aula of
lor ida with espooisl reference to the Miocene
"
Lambada or
*** parts l»a,
Incr T-roe
..,.a s vol, S,
of Kaila::
!»»%* Of
-I^o3,
"
'
.
Jusca fr-
.
rtlary
cr^
arid
Pleistocene
Oalapa^oi
la,
iifornia
-ai,, proc, ser. 4, vol, 17, no, 4, pp.
aa«*uia t pi, s-7, 1986,
.i:>;Leal society of enterics. «^o logic map of South
erica** (seal© l:5,00C,0u0, In colors}", 19M.
Oala,
araat, v*s# , iv t* a. ,- of the marine
Pliocene i
'eistocene 3&>lluses n*
fornia and
(scant re ;0n5...," o Soc, Kat* Hist.,
Mem. , vol, 1, 1911*
,„.
.
242
Grsybovski, 4. n>i;* Pertitrablagerungen
dee ncfrdliohen
*
Peru and ihr® Molluskenfanns,1 Beitr. dsol. Bal.
1. Jshr* kin. Osoi. v. Pa!*, Beiiage^
Band 12, p, #10-644, pis* lh-£O, 1889*
;. U. and M. 0* Israelsky* "Contribution to the
Tertiary paleontology of Peru," California Acad*
ML, 4th ser*, vol. 14, no. 8, pp., 57-75, pis.
7-8, 1925.
ana
Hedberg. fi* D.
-.tra ti.gr aphy of the*Rio Qaarecual section of northeastern ?sasaa«la t Osol* 80s. &&er,
Bull*, vol. 48, no. IS, pp. 1971~a084,
1957*
,
fiartlalm, L.
-
G,
and 4. iff. Strong. -Eastern
elfla expeditions of the hey 'fork aooloalcal aociety, >JCII.
: ollusks from the west co**at ot r1; so ci Central
saarisa, Part I,* Zoologies, vol. £5, pt. 4. mmm
her 31, 1940*
_*
£_|£*l
mmm
m'Pl^.*t
I^Tt $ s VOl. 33, J)% m 4, ©3011111-
I or 31, 1946.
Iv, 1949*
♥
f**t 7, VOl * 43, ft* E*
AUgUS
■
Hodson, Floyd. *f®aa^u#ia» and Caribbean Turritellas,
Lull* m®r* Beleo*, vol, 11, no, 4b, 1916*
__
tycoon, and G. B* Harris*
t li. K.
Venezue?^
lan
ana Caribbean --3 lusl-'S,* ibid,, vol, 13, no, 49.
1957.
a,
!
1a m,
.
..
vol. 16,
:
«
*
**le
"fiJoao Venezuelan Kolluslts,
nos. l«5~C0, 1931.
""■■"--Da,
Husks from ti
i -."
of 0--1 5 1
Sat* Hist*, jfrens., vol,' 10, no, 2
3-4, figs, 1-5, 1943*'
j.
"
-3ccns
v lain silt
a.
pis.
.
aai :. I
-n. f,ftot@s on the Gatun formation f.M! cans), Panama Canal &one,* Oeol* ooe* Haer.
Bull,, vol* 57, p* 1260, I^cc.rber, 1940,
Klalnpell, S,
:r,
AT,
i-ssoe,
"Xiocene stratigraphy of
Pat. G^ol* , 1988*
...
ornia,
f, ;v. falser. wTne geology and
aleoni
the Cuenc.
ss-Bibllin region,
. " .
wiasaa of CalSar i
-ador,* Bull. Amur*
Paleo., vol* S6, no. 100, 1941*
Mddle. R.
,
;
;of
243
1
*
%
;: s * Geol
s. - J. C**
*
- !os ana genera
of Tertiary Hoatlnaa
urv,, Prof*, lap, 189-i, pp, Em,
$
"
-
:
'I ''V-'iiQnclattii'ftl
-tiamrai «r<t»
unift
- t'
estrc
"
i
.,ue,'* Jour, Paleo., vol* E3
?\?
aUry
-.T---i
_r
rs
do. a
S
-
-i
---I
&»rieaa
tii\ ancelXerli-
>"■
j*
c
j
t»i
to the paleontology of
i
/f contribution
«ABicaG,
. , p^at. i>ci. Philadelphia,
lour.*
sera i
p vol, «, )&, 23-112, 9 pis,, 3:i£
-
#
#
<er,
Pelou., vol* 5,
»_!! t
a
ri'"
*
i sections and
no,
£9, 1917
-.ribution to t
yTi%tmm)m ibj£.
lfc
**
'
fossils, Bull.
9
)sontoloBy of
, vol. It, no.
42,
rrltellaa from the . &elric
pub,, Bull.
|. Oi
1-214, pis, 1-41, U4l.
"
?*
f
m
M^Z
liar ll
® f *J£
:
f
-"
■
jr&xen,^
aollascan fauna of tha late Tar?
!
Connecticut
£"*»! pl. 0-7, IS7O* Acad* :ici., vol* 8
—205,
gf*
.
4-V,
.90sync line oi
, y,-~er.
*
*
*
*
T.^mmrmmmmmmm*
w*
iv*
*»
WA-,
*
f
in
-„, „JV«3 A «.*,
Pull "
www*. , *3*t«fcJk.
I -ssoc. I-et. Oeol.
m*
*.
84,
pp, 1998*8006, 1950*
no. 10,
inoaifcado,
; m - from tr-a n*»i»h:-eru*
c
a, oi
-. *rrupi s
tof Chocd, Colombia *
4. _n. «wur t) vol, 46, no,
555 Trans,
i-aioo* boa. c- pan, no. 96), pp. 517-630, pl.
29.
aau6ii
i
/juerica,
_ _ .J;
wf
.
m,
Cm,
1*
a.
j.cirthern Cost-
-3 3;
1
.11* £mer. Paleo., vol* 9, no. 39
~prr„??f!:
n;?*e/EJy
and fana»
-
#
1940, proc,
l
'
t e
?
;
Lea *
,f
paleontology of northern
iocaa..- ibM., vol, If,
'
deposits of northwestern
Mar* aei. coagr., Bth,
vol. 4 f pp. 881-887, IMS.
America
ton"!*
"t
244
Olsson, a, a*
n
m%i£
tectonic intarnreta tions of the
St ra 3 util to^*a,«
Amur* Sci*
Pt/
' ass tegton, ?
ft flVJlt^"?
1940, Proc, vol* 4 bb
££«
t??^*! J
marker,
M«rr«.
T?
1949
**
2m
'
\■'
"" : anslls of
t,e
ill. laer* Pala©.,
i0 *
southwest coast of
vol* as, no, 95.*
, K. Oabb's fertlarv -i
1
...uingo,- .cad. Mt. .ci
ri.J
.■lpbia, Proc, vol. 73, pt, 2 po* ay^
0 2-j
43§ *
M
PP
Pas*
10-47, 19ZZ*
"
"Saviaion of
y*
l«fc?.^
"?"
-
i
:w:i
Johnson*
--sue," Ijyhu
.,
——\\
-_
l'
!^a
?
W
a*
«
'
ttl&».
A
.
llusca o. t a
,anto
vol*. 59, pp. IOG-fcCz.
Pliocene fauna froa
3, pp.
U79 a
.
«*"
a-cent and fossil
Poaell^ ......fa. * - e6 -family slaail
.-airiciae,"
\ m%.
Ty
T
G
a*,
\
Bull., no, 8, July 15, I»4E*
>
!
-
.-sningaoa, i96o*
':'-*. -t
:**,
5i aort crn South uaeriaa,
.>t*T* wd. Coia-ar,, Bth,
Pros*., vol. 4,
-.
«p,
.M
'-
-xian inwro"-
-^eu.
,
»«"
m
<*aa .
kuala f
j*Cih. , vols,
54.-5S t 1934*
c sollusten
arniocaeni
■**"«"!
"
i,n
frlnifti
**>*■*»
"
pp*
515-571,
aer
fUf wa
Peleoiit,
Aa-aafcisfetMi
&*It!sob- Heat-Indian!
Gteasll,
Basel, vol* 54,
of Barbados and its bearing
£f!t*
*Jl
r^l«afana
structure
.rt! li«an~€eribbea»
tmvtlZ S ! r* i soc* i*t.ofQwl
Bull., vol* 24,*
r^ion
xo4ts-i©io, 19 40,
.kp*
-
-Fossil and Raeent speei.s of th. oele
e r
from tm ifcoifia
't : -t'also.,»advoIT
fseur.Ua
23, no. G, pp. 577-5*3,
c«£t
tr
?
#I
245
Sfcappara, George.
-.tes on the Miocene of "seuador,"
18, pp* 671-
ioc Pet. Geol*, Lull., vol.
__
"Tb* ecology of sotttbaaatarn Ecuador,
Murb|
.Jo*, London, 1937,
T.
Smith, Maxwell. ffEast coast marine shells.
Brothers, Inc., 1945.
*r<ls
Spieker , ft. <l. "The paleoi tc loi y of the Zanrl'taa formation of the MartB Peruvian oil timl&m* m Johns
Hopkins Pniv. studies in Ceol., no. 3, 1922*
"c,. I) c aleropalaontology in coastal
laaaaort n _Jour. M»»* t vol. 88, no* s, pp. 113-151,
pis*. £4-26 , 1941
-,a-rt, Ralph, *f Gabb»a California type gastropods,"
.cad. Let. oei. J nilacelpfala, Proc, 'vol, 78, op
£87-447 pl, 80-38, I„*.C
Stainforta, 8. U*
.
,
ftL
"Gabb* a California
**
.
I
=ac111tranche, i*ca<j..
xiid * no * «j 19oQ
rctaeoous and -Tertiary t.
at, Sci. Philadelphia, Spec
Tbalaann, B. a.
cropsiaontologv of Miocene Irosreso
formation, southwestern Ecuador** (abstract), Geol.
c Asar*, Bull*, vol. 57, pt. a, p* 1236, 1946*
Tsobopp, fi* a. wGeologisclie skizze yon leuitCer, ' fereln.
Sehvalftsr. I"etrol.-Geol. v. Ingen. bull., vol* 15,
no, 48, pp* 14-45, 1948*
*
seeks, L. o.
sograplij of South Aseriea,1 Aaer.
Assoc Pat. Oeol., Bull*, vol* 11, no. ?, pp. 1194*
12*41f 1^47*
~
--.,iocena fcolluaca
ieisbord,
S*
northern Colombia,
*
lull* kmet Paleo* , vol 14, no. 54, 1929,
7
MLt. feoaoro.
\i<torr:*yUi
Leipzig, 1892,
y
geologfa del
..ci.^.or.
r.
i\ **a_iocene moHusks from Bo mien, Jamaica*
peleeypods and seapaopods. m Carnegie Inst* of
lasMagtoa, pub, no. 366, 1988*
uoarlxi(r,
__
_
"Ansrlees Tertiary mo Husks of the genus ClemenM¥ f « U.S.. Oeol. Prof, yap* 147, pp* 2i5-AB. rj^-"-14-17, 1986*
'iiiocsns molluelrs from Bowmen, Jamaica, part Si
gastropods and discussion of results," Carnegie
Inst, of
.
ton, pub, no. 385, 1988.
|-farviell«
JsaLef
Stenographic
BANK OF AMERICA
Service
BUfLDING
PALO ALTO. CALIFORNIA