Daniel J. Chure, Observation on the morphology and

ORYCTOS,
Vol. 3 : 29 - 37,Décembre
2000
OBSERVATIONS
ONTHEMORPHOLOGYAND
PATHOTOGY
OFTHEGASTRAL
BASKETOF
ALLOSAURUS,
BASEDONA NE\rySPECIMEN
FROMDINOSAUR
MONT]MENT
NATIONAL
Daniel J. CHURE
DinosaurNationalMonument,
Box 128,Jensen
UT 84035,USA
[email protected]
Abstract: A well preservedandcompletegastralbasketof Allosaurus(DINO 11541)correctsa numberof earlier
misinterpretations
of this structurein Allosaurus.Thebasketconsistsof eighteenrowsof gastralia.Thefirst row has
only oneelementper sideandthesedo not overlapmediallybut ratherform a craniallyfacingnotch.All otherrows
havetwo elementsper side,themedialonebeingthelonger.Theright andleft medianelementsoverlapat the midline of the basket.Allosaurushasonly four elementsper gastralrow.
Previousinterpretations
for Allosaurushavebeenashigh asnine elementsper row. The supposed
fused,V-shaped
mediangastralelementis now knownto be a furcula.The supposed
four lateralelementsin USNM 4734areactually all part of a singlemedianelementinjuredduringlife andhealedas a seriesof pseudoarthroses.
The presenceof
pseudoarthroses
andcallusesin othermediangastralelementsof USNM 4734 furrhersupportthis interpretation.
The presenceof similarpathologiesin the gastraliaof anotherspecimenof Allosaurus(USNM 8367)aswell asin
the dorsalribs of a specimenof Acrocanthosaurus
atokensis(SMU 74646)suggeststhat suchinjuries were not
uncommonin allosauroidtheropods.Theseinjuriesmay be the resultof eitherstruggleswith prey or intraspecific
behavior,suchaskicking or head-flankbutting.
Key words:Dinosauria,Theropoda,Osteology,
Allosaurus,Gastralia,Jurassic,Morrison,Pathology
Observationssur la morphologieet les pathologiesde la cagegastraled'Allosaurusbasées
sur un nouveauspécimendaDinosaur National Monurnent,Etats-Unisd'Amérique
Résumé: Unecagegastralecomplèteenbonétatdepréservationd'Allosauruspermetdecorrigerd'anciennes
interprétationsde cettestructurechezce dinosaure.Le cageen questionconsisteen 18rangéesde gasfralia.La première rangéeprésenteun seulélémentpar côté; les deuxélémentsde cettepairene serecoupentpasmédialement
mais
formentuneencochedirigéecranialement.
Les auffesrangéespossèdent
deuxélémentspar côté,le médianétantle
plus long. Les élémentsmédiansgaucheset droitesserecoupentsur I'axe de symétrie.Allosaurusne possèdeque
quaffeélémentspar rangéegasfrale.
Les anciennes
pourA/Iosaurusont proposéjusqu'à 9 élémentspar rangée.L élémentgastralsuppointerprétations
séfusionnéen formede V s'estrévéléêtreunefurcula.Les quaffeélémentslatérauxsupposés
de USNM 4734sont
enfait lesfragmentsd'un uniqueélémentcentralfracturédurantla vie deI'animalet cicatrisésousformed'unesérie
depseudarthroses.
La présence
depseudarthroses
et decalssurd'autresélémentsdela sériegastraledeUSNM 4734
soutientcetteinterprétation.
La présencede pathologiessimilairessur les gasfraliad'un autrespécimend'Allosaurus(USNM 8367)et sur les
côtesd'un spécimend'Acrocanthosaurus
atokensis(SMU 74646)indiquequede tellesblessures
n'étaientpasrares
chezles théropodes
allosauroides.
Cesblessurespeuventêtrele résultatde luttesavecdesproiesou de comportementsintraspécifiques
tels quedesruadesou descoupsde têtecontreles flancs.
Mots clés: Dinosaurta,Theropoda,Ostéologie,
Allosaurus,Gastralia,Jurassique,Morrison,Pathologie
29
ORYCTOS.
Vo1.3.2000
INTRODUCTION
Allosaurus is the most abundanttheropodin the
Late JurassicMorrison Formation (Foster & Chure,
1998,2000 ; Chureet a1.,2000).As a resultof this
rich fossil record it is one of the best known theropodsandhasbeenthe subjectof severalmonographic
studies(Gilmore,1920;Madsen,1976;Chure,2000).
Becauseof this Allosaurusis a critical taxon in many
phylogeneticanalysesof the Theropoda.
However, the discovery of a spectacularlycomplete and articulated specimen of Allosaurus in
Dinosaur National Monument has clarified several
aspectsof Allosaurusmorphology;namelythepresence
of a furcula, the compositionand morphology of the
wrist, and the gastralbasket.Both the wrist and the
furcula have already been described (Chure &
Madsen,1996;Chure, 1999,and in press).The presentreport focuseson the gastralbasket.
INSTITUTIONAL ABBREVIATIONS
AMNH = AmericanMuseumof NaturalHistory NY.
BYU = EarthSciences
Museum,BrighamYoungUniversity,UT.
CMNH = CarnegieMuseumof NaturalHistory PA
DINO = DinosaurNationalMonument,UT.
MOR
= Museumof Therockies,
MT.
SMU = SouthernMethodistUniversity,TX.
USNM = UnitedStatesNationalMuseum,Washington,
D.C.
B
Figure 1. Gastral basket of Allosaurus (DINO 11541) in dorsal view.
A. Position of basket between pectoral and pelvic girdles. B. Close up of median and lateral elements.Scale bar in cm.
30
CHURE - OBSERVATIONS
ON TIIE MORPHOLOGYANDPATHOLOGY
OFTIIE GASTRALBASKETOFALLOSAURUS
DESCRIPTION
The specimen(DINO 11541)is a new speciesof
Allosaurus, currently under description (Chure,
2000). It was found in the upper portion of a 60 cm.
layer of conglomerateat the base of a 1.4 m deep
paleochannelin the Salt Wash Member of the
Morrison Formation of Dinosaur National
Monument (Hubert & Chure, 1992). The skeleton
was in the hyperdorsoflexedattitudestrongly suggestive of desiccation of the body before burial
(Gradzinski, 1969; 'Weigert, 1927), which probably
explainshow the skeletonremainedarticulatedin the
high energyriver environment.Part of the right (stratigraphically up) forelimb and hindlimb and the right
side of the skull is missing, along with the middle
part of the tail. The right side of the gastral basket
was damagedbefore discovery and many of the lateral elementsaremissing or incomplete.However,the
gastralbasketwas in-placebetweenthe pectoralgirdle andpelvis (fig. 1).
l2
.,," :.15
t7 t6,e
Si1'':'",
- :!:- '
t
t'
l8
t7
t5
EI:I:n
l3
B
t2
&
Figure 2.
Gastral basket of
Allosaurus
(DrNO 11541)
in ventral view.
A. View showing
narrowing of basket
towards caudal end.
18
B. Close up showing
displacementof
contact between
median elements.
Numbers refer
to gastral row,
numbered from
front of basket.
t7
18
16
Scale bar in cm.
31
ORYCTOS,
Vol.3,2000
rightpubis
The basket is rn a
large block of sandstone
along with the vertebral
column, left dorsal ribs,
the left scapula, and the
left femur. As a result. the
cranialhalf of the basketis
exposed in dorsal view
and the caudalhalf in ventral view. The cranial half
of the cuirassis broad and
flat (possiblydue in part to
postmortem dorsoventral
flattening), with a gentle
dorsal curvature.The caudal part is narrower and
more V-shaped in crosssection(figs. 1, 2) and on
the better preserved left
side the caudalpart of the
basket can be seen to be
lateral to the pubic boot
left pubis
Figure 3. Medial view of left lateral elements of gastral basket in DINO 11541. Note their position
lateral to distal end of left pubis. Numbers refer to gastral row, numbered from front of basket.
(fie.3).
The basket contains
eighteenrows of gastralia.
The first row is different
than the rest of the cuirass
in severalways (fig. 4). In
the flrst row there is only
one elementon each side,
ratherthan two. Theseelements do not overlap
medially. Instead, the
medial end of each is a
vertical, oval surface and
the right and left gastralia
meet such that their
medial faces form a cranially facing right angle
notch (fig. 44, C). There
are no grooveson the cranial margin of these elements for contact with
lateral gastralia, further
confirming that the first
row consists only of the
medianelements(fig. aB).
32
CHURE - OBSERVATIONS
ON THE MORPHOLOGY
AND PATHOLOGY
OFTFMGASTRALBASKETOFALLOSAURUS
In gastral rows two
through eighteenthere are
four gastraliaper row, two
median and two lateral
(fig. 5). There is no
median V-shapedelement
like the one reported by
Gilmore (1920) in USNM
4734. The median elementsare longer and more
robustthan the lateralones
and slightly sinuous in
dorsalor ventralview (fig.
1). The medialend is caudally curved and expanded (fig. 2). The medial
ends overlap such that in
ventral view the right
median gastraliumis ventral to the left. The ventral
surfaceof the medial end
of the left gastralium is
convex and this fits into a
concavity on the dorsal
surfaceof the medial end
of the right gastralium
(fig. 2B). Laterally the
medianelementstaperto a
point (fig. 5B). A groove
on the cranial face of the
median gastraliais for the
contact with the lateral
element(figs. 58, 6).
There has been postmortem separation between the medianelements
of the cuirass(fig. 5).
The ventral overlappingof the right medianelementsis bestseenin mediangastralpm I7. Therehas
beenslight disarticulationof this contactin segments
18 and 16.In segments13,14, and 15 therehasbeen
considerablecranial shifting of the left median elements,to the extentthat, for example,the medial end
of left mediangastralium15 overlapsthe shaftof right
median gastralium 14. This offset continues, to a
varying degree,through gastralsegment2.
The lateral elementsare shorterthan the median
33
gastralia(figs. 1A, B, 5B). This is typical for theropods, although the condition is reversed in some
maniraptorans (Norell & Makovicky, 1997). Each
lateral elementhas a wide, truncatedlateral edgeand
tapersmedially (fig. 5B). Each lateral elementhas a
groove and fits in a groove on the craniodorsaledge
the medial element (fig. 6). This overlap between
median and lateral elementswas not strong,as there
is some separationalong this contact in all gastral
rows in DINO lI54l.
ORYCTOS,
Vol.3,2000
However,the V-shapedelementin USNM 4734,
of which only one was found, is now known to be a
furcula, basedon the in-situ furcula found in DINO
I754I (Chure & Madsen, 1996). This drops
Gilmore's count to six or possiblyeight.Examination
of the row which Gilmore thought to preserve four
lateral gastralia shows that the three proximal segments are likely to be parts of a single, medial gastralium, which was damagedduring life and healed
pathologically.
The gastraliaof USNM 4734 show a number of
Figure 6. Crosssectionof medianand lateralpairs of right gastralia breaksandpathologies.Someare greenbreakswhich
in rows 16 and l7 of DINO 11541.drawnfrom a brokensurface. occurredat the time of deathor post-mortem(frg.7)
Crosssectionof row 16 at about 185 mm lateralfrom midline of basand need not concernus any further. Other patholoket. Crosssectionof row 17 at about160mm lateralfrom midlineof
gies are the result of injuries sustainedduring life
basket.Spacingbetweenrows 16and 17reducedfor illustrativepurwhich subsequentlyhealed.These are of two types.
poses.le = lateralelement,me = medianelementScalebar = 1 cm.
The first are healed fractures indicated by calluses
(fig. 8C, D, E). The second are pseudoarthroses,
DISCUSSION
breakswhich during healing formed moveablejoints
(fig. 84, B). Several of thesepseudoarthroses
have
The gastral cuirassof DINO lI54l is the most well formed ball and socket articulations.In all thecompleteand best preservedfor any non-coelurosau- ropods the contactsbetweenmedial and lateral gasrian theropod.GastraliainAllosaurus areusually iso- tralia arelong, overlapping,sliding contacts.Ball and
lated and incomplete (Cleveland-Lloyd Dinosaur socketjoints are unknown in gastralbaskets,further
supportingthe interpretationthat theseare pseudoarQuarry collections in the University of Utah, MOR
693,AMNH 5753,CMNH 33903,USNM 9367).An
throses.
exceptionis a partial basketin USNM 4734 desciThus, anomaliesin the gastralbasketof USNM
bed by Gilmore (1920). However, in light of DINO
4734 canbest be interpretedas being the result of an
7154I several enors of interpretation can now be injury during life to the mediangashal elements.The
identified in that work.
subsequentregular movement of the gastral basket
The gastral basket of USNM 4734 is still in
during breathingandlocomotionresultedin the devematrix, in threeblocks which fit together.It hasbeen lopment of a number of pseudoarthroses.
This interdorsoventrallyflattenedand retainsnone of its origipretation, coupled with the recognition that
nal curvature.The basketis exposedin ventral view, Gilmore's median element as a furcula, reducesthe
although some of the elements have been rotated count in USNM 4734 to four elementsper row, a
along their long axis and someare displaced.Most of
median and lateral element on each side. This is
the elements preserved are median and lateral ele- consistentwith what is now known basedon DINO
ments of the right side, although there are a few scat- I754I and is typical for theropods(Claessons,1996).
tered left median elementspresent.
There is a growing interest in how broad patterns
Based on his study of USNM 4734 and 8367 of pathologies may provide insight into vertebrate
Gilmore (1920) estimated that there were at least paleobiologyat varioustaxonomiclevels (Rothschild
seven,and possibly nine, gasûalia per row (at least & Martin, 1993;Rothschild& Tanke, 1992).Among
tlree, and possibly four, laterals and a V-shaped dinosaurssuch analyseshave been done for ornthismedianelement).This is an exceptionallyhigh count, chians but not yet undertaken on the same scale for
the highest for any theropod.Gilmore (1920: p. 54) theropods.Nevertheless,it may be significant that
found support for this high count in one gastral row
callusesand pseudoarthroses
in the gastralialike those
in USNM 4734 whtchhe thought preservedfour late- in USNM 4734 are also are present in the scattered
rals on one side(figs. 7, 8A, B).
gastralia of another Allosaurus fragilis specimen,
34
ON THE MORPHOLOGY
AND PATHOLOGY
OFTHE GASTRALBASKETOFALLOSAURUS
CHURE - OBSERVATIONS
6
/
,(,
(USNM 4734).A. Photographof basketin ventralview. B. Explanatoryline drawing.cl, c2,
Figule 7. Gastlalbasketin Allo.;uurus.fizrgllls
c3 = ciilluseson nredialsastralelements,g = greenbreaks,p = peudoarthloseal
surfaceson mediangastralelements,1,2,3,4= 4lateral gastral elementsas identifiedby Gihnore( 1920).Scalebar in cm.
USNM 8367(Gilmore,1920:fig. 38).This suggests
that injuries to the flanks and belly region may not
have been uncommonin Allosaurusand that those
injurieswere not alwaysfatal.Theseinjuriesmay be
the result of intraspecificbehaviors,such as headflank butting or kicking (Paul, 1988), or possibly
from struggles during the subduing of prey,
although we have no direct knowledge of what
Allosaurus preyed on or even if it was a predator.
Flank injuries may be of broad behavioralsignificance,at leastamongallosauroids,as Harris (1998)
has reported a series of calluses and pseudoarthroseson the dorsalrib shaftsof Acrocanthosaurus
atokensis.
Finally, the discovery of an in-place furcula in
DINO I154I led to the identification of a furcula in a
numberof specimensof A/losantrus,both described
(Chure& Madsen,1996).Alcoberer
andundescribed
al. (1998) reporteda furcula in an unnamedcarcharodontosauridallosauroidfrom Argentina. However,
one can not jump to the conclusionthat any V-shaped element is a furcula, becausethe few gastral
basketsknown in basaltetanurinesshow sienificant
morphologicalvariation betweengenera,including
the presenceof V-shapedmedianelements.
The gastralbasketin Ac rocanthosaurus atokenhas
sis
at leastfour V-shapedmedianelementsin the
caudal region but only paired overlappingmedian
elementsare presentin the cranial region (Harris,
1998). These V-shapedelementsare clearly fused
median gastraliaas they have grooves along their
cranial marginsfor contactwith the medial part of
the the lateral gastralia. Thus Acrocanthosaurus
retainsthe generaltheropodpatternof four elements
per row.
(EudesIn
Poekilopleuron bucklandi
Deslongchamps,
1838)thereareat leastsevenV-shaped median elements but, in contrast to
Acrocanthosanrlts,they are in the cranial half of the
basket and are more sinuous than in
Acrocanthosaurus.The only known specimenof P
bucklandi, including the gastralia,was destroyedin
an Allied bombing raid on Caen in 1944 (Taquet
1998). Fortunately,a cast of the baskethas recently
been rediscoveredin Paris (Ronan Allian, pers.
comm. 2000), and is currently inder study.
35
ORYCTOS.
Vol.3.2000
Finally, two V-shapedmedian gastral elements
havebeencollectedfrom the Dry Mesa Quarry in the
Morrison Formationof Colorado(fig. 9). While these
elementsare not referableto Allosaurus,large specimens of the neoceratosaurianceratosaurus sp. and
the spinosauroid Tbrvosaurus tanneri are known
from the site (Britt, l99l). This suggeststhat median
V-shapedgastralelementsmay have a wide distribution in basaltetanurines.
Iateral element
medial element
.l
C
ll
D
Fi_cure8. Pathologiesin the the gastraliaof Allosuurus.frugilis (USNM 4134).A. Close up of rhe element interpretedby Gilmore
( I 920) as showing fbur gastraliaon one side of basket.as u'ell as severalsegmentsof median elementswith pseudoarthroseal
surfàces.B. Explanatorydrawingof A. C. Closeup of callus(c I in fig. 7B). D. Closeup of pairedcalluses(c2 in fig. 7B). E. Closeup
of callus(c3 in fi-e.'lB). 1,2,3,4,= Gilmore'sinterpretation
of foulelementson one sideof basket.Lateralelement,medianelement
= identificationin this work of Gilmore'selements.
Figure 9. Likely V-shapedmediangastralelements
from the Dry Mesa Quarry in the Morrison
Formation of CO. Ventral view. A. BYU 5115 B.
BYU 12926.Scalebar in cm.
36
CHIJRE - OBSERVATIONS
ON T}IE MORPHOLOGYAND PATHOLOGYOFTIIE GASTRALBASKETOFALLOSAURUS
Paleontology
16 (3): 573-577.
CLAESSONS,L.P.A.M. 1996.Dinosaurgastraliaandtheirfunction
in respiration.Joumal of VertebratePaleontology16 (suppleThis paper is an outgrowth of a Ph.D.
mentto no. 3): 284.
Dissertationat Columbia University on the systema- EUDES-DESLONGCHAMPS,J.A. 1838. Mémoire sur le
tics of the theropodfamily Allosauridae.I thank Drs.
Poekilopleuronbucklandi, grand saurienfossile, intermédiaire
Malcom McKenna and Eugene Gaffney for their
entreles crocodileset les lézards;découvertdansla carrièrede
la Maladrerie,prèsCaen,au moisdejuillet L835.Mémoirede la
encouragement
and supportof that study.Thanksalso
sociétélinnéennede Normandie6:37-146.
go to Dr. Mark Norell (AMNH), Drs. Bob Purdy and
FOSTER,J.R.& CHURE,D.J. 1998.Pattemsof theropoddiversity
Michael Brett-Surman (USNM), Dr. Jacques
and distributionin the Late JurassicMorrisonFormation,wesGauthier (YPM), Dr. Richard Stucky (DMNH), Mr.
tern USA. Abstractsand Programfor the Fifih International
Ken Stadtman(BYU), Dr. Jack Horner (MOR), Dr.
Symposiurnon the Jurassic System,Intemational Union of
Richard Cifelli (OMNH), Dr. Dave Berman
Geological Sciences, Subcommis
sion on JurassicStratigraphy,
Vancouver,
British Columbia,Canada:30-31.
(CMNH), Mr. Chuck Schaff (INf:CZ),and Ms. Laurel
in 2000.An ilium of a juveCasjen (UU) for allowing me to study specimens
(Dinosauria,Theropoda)from the Morrison
rrl.leStokesosaarus
under their care. My thanks to Ann Elder and Scott
Formation (Upper Jurassic,Kimmeridgian),Meade County,
Madsen (Dinosaur National Monument) and their
SouthDakota.BrigharnYoungUniversityGeologyStudies45:5-10
volunteer crews who labored long and skillfully for
GILMORE,C.W. 1920.Osteologyof the carnivorousDinosauriain
many yearsin excavatingDINO Ll54l and skillfully
theUnitedStatesNationalMuseum,with specialreferenceto the
generaAntrodemus(Allosauras) and Ceratosaurus.United
preparedthe gashal basketof the specimen.Support
States
NationalMuseumBulletin 110:159pp.
project
for this
camefrom the National Park Service
GRADZINSKI, R. 1969.Sedimentation
of dinosaur-bearing
Upper
and DinosaurNational Monument.
Cretaceousdeposits of the Nemegt Basin, Gobi desert.
Palaeontologica
Polonica2l: 148-229+ platesXXXVU - XLU.
REFERENCES
HARRIS,J.D. I 998.A reanalysisof Acrocanthosaurusatokensis,its
ALCOBER,O.; SERENO,P.C.;LARSSON,H.C.E;,MARTINEZ,
phylogeneticstatus,andpaleobiogeographic
implications,based
R.N. & VARRICCHIO,D.J. 1998.ALate Cretaceous
carcharoon a new specimenfrom Texas.NewMexicoMuseumof Natural
(Theropoda:
dontosaurid
Allosauroidea)
fromArgentina. Joumal
Historyand Science,Bulletin 13 75 pp.
ofVertebratePaleontologyl8 (supplement
to no. 3): 23A.
HLIBERT,J.F.& CHURE,D.J.1992.Taphonomyof.anAllosaurus
BRITT, B.B. 1991.Theropodsof the Dry Mesa Quarry(Morrison
quarryin the depositsof a Late Jurassicbraidedriver with a graFormation,LateJurassic),
Colorado,with emphasis
on theosteovel-sand bedload, Salt Wash Membeq Dinosaur National
logy of Tonosaurustanneri.Bigham YoungUniversityGeology
Monument, Utah. /n.' WLSON, J.R. (ed.) Field Guide to
Studies37: l-72.
Geologic Excursions in Utah and Adjacent Areas of Nevada,
CHLJRE,D.J.2000.A New Speciesof.AllosaurusfromtheMorrison
Idaho, and llloming. Utah Geological Survey,Miscellaneous
Formation, Dinosaur National Monument (UT-CO) and a
Publication92-3:375-381.
Revision of the Theropod Family Allosauridae. Ph.D.
MADSEN, J.H. 1976.Allosaurusfragilis: A RevisedOsteology.
Dissertation,Departmentof EarthandEnvironmentalSciences,
UtahGeologicalandMineral SurveyBulletin 109:163pp.
ColumbiaUniversity,N.Y.C.,N.Y.: 1200pp.
NORELL, M.A. & MAKOVICKI P.J.1997.knportantfeaturesof
1999.Thewrist of Allosaurusandtheevolutionof the
the dromaeosaurskeleton:information from a new specimen.
semilunatecarpal.Joumal of VertebratePaleontology19 (supAmericanMuseumNovitatesno.3215:28pp.
plementto no. 3): 384.
PALIL, G.S. 1988.PredatoryDinosaursof the World.Simon and
n press. The wrist of Allosaurus (Saurischia:
Schuster,
N.Y.: 464 pp.
Theropoda),with observationson the carpusin theropods..ln
ROTHSCHILD, B.M. & MARTIN, L.D. 1993.Paleopathology:
GALIHIER, J.A. (ed.) New Perspectiveson the Origin and
Diseasein theFossilRecord.CRCPress,Ann Arbor: 386pp.
Evolution of Birds. PeabodyMuseumof Natural History Special
ROTHSCHILD,B.M. & TANKE,D.1992.Paleopathology
of vertePublicationno. 5:
brates:insightsinto lifestyle and healthin the geologicalrecord.
_____BRITT,
B.B.; FOSTER, J.R.; MADSEN, J.H. &
Geoscience
Canada19: 73-82.
MILES, C.A. 2000,New recordsof Ceratosaurus,
Torvosaurus, TAQUET, P. 1998. Dinosaur Impressions.Postcardsfrom a
Coelurus,arrdStokesosaurus
artdtheir implication for theropod
Paleontologist CambridgeUniversity Press:244 pp.
community structureandbiozonationin the Late Jurassicof the
WEIGELI, J. Dn. RezenteWrbeltierleichenund ihrepaliiobioloWesternInterior.Joumal of VertebratePaleontology20 (supplegischeBedeunng.l-nipzig: 277 pp. @nglishtranslationpublished
mentto no.3) : 354.
in 1989asRecentVertebrateCarcasses
and TheirPaleobiological
& MADSEN, J.H. 1996.On the presence
of furculae
Implications.Universityof ChicagoPress:188.pp.).
in somenon-maniraptoran
Theropoda.foumal of Vertebrate
ACKNOWLEDGEMENTS
37