Lab 3 - Testudines

It’s Turtle Time!
Lab 3 - Testudines
Cladogram
General characteristics
Morphology
- Rigid shell enclosing the
internal organs
-Carapace = dorsal part
- Plastron = ventral part
- Shell is composed of dermal
bony elements covered by
keratinous scutes or leathery
skin; the shell incorporates ribs,
vertebrae, portions of pectoral
girdle
- Plastron can be rigid or hinged
(around 300 species)
General Characteristics - Scutes
Marginal
Nuchal
Costal
Supracaudal
Vertebral
PLASTRON
General characteristics
Morphology
- Shell shape – ranges from domed (in terrestrial species) to flat or
hydrodynamic shaped (aquatic and marine species)
General characteristics
Morphology
- Absence of teeth (keratinous beak instead)
- Freshwater species carnivorous, omnivorous, or herbivorous; terrestrial
usually herbivorous.
- Limb structure – flippers (marine species), webbing between digits
(freshwater species), stout limbs with thickened pads (terrestrial species)
General characteristics
Reproduction
- All species are oviparous; females dig nests
or lay eggs on land; no parental care; very
elaborate courtship rituals
- Males have a penis (protrusion of cloaca)
- Temperature sex determination in most
species
- Long-living creatures, low recruitment, late
sexual maturity
Suborder Pleurodira
side-necked turtles
Family Chelidae - snake-necked turtles
Family Pelomedusidae - African side-necked turtles
Family Podocnemidae - South American
side-necked turtles
Family Chelidae
Australoamerican side-necked turtles
-50 species; aquatic; carnivorous
- Australia, New Guinea, S. America
-matamata – suction feeding (movie)
- Australian Chelodina rugosa – lays
eggs underwater
Family Pelomedusidae
African side-necked turtles
- Africa, Madagascar, Seychelles
- 18 species; aquatic; carnivorous
- 12-50 cm length
- Can aestivate in seasonally dry places
Podocnemidae
Madagascar, S. America side-necked turtles
- 8 species; herbivorous
- flat shells; active swimmers
- suffer from eggs overexploitation
- largest turtle (Stupendemys)
Suborder Cryptodira
hidden-necked turtles
Family Carettochelydae
Pig-nosed turtles
- 1 species (Carettochelys
insculpta); up to 70 cm
- S. New Guinea, NW
Australia
- Herbivorous
- Highly aquatic
-carapace covered in soft
skin; paddles with claws;
fleshy proboscis
Family Trionychidae
softshell turtles
- 26+ species; up to 130 cm length
- carnivorous; fully aquatic; strong swimmers
- carapace covered in leathery skin, flattened; fleshy lips
Apalone spinifera
spiny softshell turtle
- Rivers, lakes, reservoirs, bays with soft
muddy or sandy bottoms
-up to 50 cm; males smaller and have
spots; bad tempered
- can breath through skin (neck, cloaca)
Family Kinosternidae
mud and musk turtles
- 22 species; aquatic; elongated shells; plastron reduced or hinged;
carnivorous; bottom walkers
- musk glands on underside; barbels on the chin
Sternotherus odoratus
stinkpot/ musk turtle
- Smooth, high-domed carapace
- front part of plastron hinged
- pointy head with 2 lines (snout  neck)
- 5-11.5 cm carapace length
- Slow-moving, muddy-bottomed rivers, streams, lakes
Kinosternon subrubrum
Eastern mud turtle
- Smooth, oval carapace
- double hinged plastron
- 13 cm length; endangered in NY
Family Dermatemydidae
Central American river turtle
- 1 species (Dermatemys mawii); 65 cm; fully
aquatic; herbivorous
- Bucco-pharyngeal gas exchange
- Nest along river edges; nests can survive inundation
Family Chelydridae
snapping turtles
- 2 species; omnivorous (they grab
anything)
- limbs, head, tail cannot be
retracted in shell
- alligator snapper – up to 80 kg
and 70 cm length; lures prey using
tongue
Chelydra serpentina
common snapping turtle
-“Bikini” plastron
- Massive head with oversized jaws
- Saw-toothed tail
Family Cheloniidae
sea turtles
- 6 species; up to 1.5 m length
- forelimbs stronger developed
- limbs transformed to paddles
- claws present
- Completely marine, except when nesting
- Nest in tropical regions
- Papillae in throat
Caretta caretta
loggerhead sea turtle
- nuchal scute touches costals
- omnivorous (mostly carnivorous)
- named for large head
Chelonia mydas
green sea turtle
- nuchal scute separated from
costals
- herbivorous
- Bask on shore
-Why the green sea turtle??
Eretmochelys imbricata
Atlantic hawksbill
- Nuchal scute separated from costals
- Carnivorous
- Most beautiful (“tortoise-shell jewlery”)
- Diet: sponges, anemones
Lepidochelys kempii
Kemp’s Ridley sea turtle
- Smallest sea turtle; rounder carapace;
smaller head
- nuchal scute touches costals
- carnivorous
Arribada nestingRidleys
Family Dermochelyidae
Dermochelys coriacea – leatherback sea turtle
- largest extant turtle (up to 2.5 m and 1300 lbs)
- carapace composed of osteoderms embedded in
skin; claws are absent
- Diet: jellyfish
- thermal inertia
Threats to sea turtles
• Predators
• Pollution
• Exploitation of meat, shells, and eggs
• Coastal Development
 Light pollution
 Loss of habitat
• Fisheries Bycatch
 Longline
 Gillnets
 Trawls
Turtle Excluder Device (TED)
Family Emydidae
pond and river turtles
- 42 species
- Freshwater, semi-aquatic, terrestrial
- Most omnivorous
- Some have hinged plastrons
Chrysemys picta
painted turtle
- Red bars or crescents on marginal
scutes, yellowish plastron, head and
limbs have yellow and/or red stripes
- up to 25 cm; omnivorous
- inhabits freshwater wetlands
- Males have longer forelimb fingernails
Painted courtships “dance”
Clemmys guttata
spotted turtle
- Black with yellow dots on carapace
and head
- Males concave plastron
- Vernal pools, uplands, wetlands
(seasonally)
- Up to 14 cm; males have concave
plastron and longer tails
Glyptemys insculpta
wood turtle
- up to 25 cm (typically 14-20 cm)
- keeled carapace; yellow-orange-red
throat, tail, and forelimbs
- omnivorous
- large home ranges (riverside
or streamside, woodlands,
meadows)
- over harvested
Glyptemys
Glyptemys muhlenbergii
bog turtle
- up to 12 cm (NY’s smallest)
- yellow/orange blotches on sides of head
- domed, somewhat triangular carapace
- inhabits early successional stages, such as wet
meadows and fens (despite name, not in acidic bogs)
- endangered in NY- habitat loss, development, pet trade
Glyptemys
Trachemys scripta
red-eared slider
- Red stripe behind eye
- Cute but EXOTIC!!!
- Quiet, deep fresh water
Emydoidea blandingii
Blanding’s turtle
- up to 27 cm; “smiley face” due to notched
jaw and bright yellow chin
-semi-aquatic
-domed carapace; front hinge on plastron
- Omnivorous
- Late maturity (14-20 years)
Graptemys geographica
northern map turtle
- Up to 25 cm
- Keeled carapace; “contour” map-like markings
- Inhabits bays and large rivers
Terrapene carolina
Eastern box turtle
- up to 19 cm; high domed carapace
with pattern;
- plastron double hinged
- open woodlands with sandy soils
- sexually dimorphic
- long lived!! (100+!)
Malaclemys terrapin
diamondback terrapin
- estuaries and salt marshes (concern
with crabbing)
-carnivorous (active hunter)
- concentric grooves on scutes; light
colored skin with dark flecks; webbed
hind feet
- sexually dimorphic
Platysternidae
Big-headed turtle
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One species: Platysternon megacephalum
Southern China, south to Thailand
Relatively small (up to 18 cm)
Small, rocky, mountainous streams
Family Geomydidae
Old World Emydidids
- 65+ species; 12-80 cm in length
- freshwater and semi-aquatic; some in
brackish water
- threatened by overharvesting
- Southern Europe to Japan, East Indies,
Central and S. America
Family Testudinidae
tortoises
- 40 species; terrestrial
- most have hard high domed carapace;
stout scaled limbs; feet unwebbed
- head and limbs fully withdrawn
Family Testudinidae
tortoises
- up to 130 cm; gigantism (Aldabra
and Galapagos)
- herbivores or omnivores
- relatively small clutch sizes; most dig
nests
- terrestriality evolved repeatedly and
independently
Your turn!