Biodiversity of Testudines, Lacertilia, Serpentes, and Crocodilia

Characteristics of Order Testudines

340 species

Anapsid

Ectothermic

Oviparous

Characteristics of Family Chelydridae

snapping turtles

large heads and limbs that cannot retract

plastron reduced

largest freshwater turtle

Distribution: north America

Family kinosternidae characteristics

musk turtles

small turtles with domed, keeled carapaces, musk glands

XY sex determination

inhabit slow moving bodies of water

only turtle species with parental care (urinate on eggs)

Distribution: N. America and S. America

Family Emydidae characteristics

pond turtles

more terrestrial, toe webbing

highly diverse

Distribution: N. America and europe

Family Trionychidae characteristics

softshell turtles

flattened shape

not really bony, leathery skin

Two subfamilies: cycloborinae (african/asian distribution), Trionychinae (N. American, Asian, and African dist.)

highly aquatic

What are toxicoferans?

proposed clade that includes venomous snakes and lizards and their non venomous relatives

characteristics of family boidae

Boas and anaconda

60 species

small to large

aglyphous dentition

interlabial pits (heat sensing organs)

Viviparous

constrictors

vestigial limbs

Family Colubridae characteristics

Common snakes

1755 species

highly diverse

aglyphous, opisthoglyphous, proteroglyphous

Duvernoy’s glands- homolog to viperid venom glands

oviparous

Characteristics of Viperidae

Vipers and pit vipers

350 species

small

venomous (solenoglyphous)

Keeled scales

heat-sensing loreal pits

left lung absent

triangle head

ovoviviparous

hemotoxic and cytotoxic

Dist: everywhere

Family Elapidae characteristics

cobras, Kraits, sea snakes, death adders

600 species

venomous (proteroglyphous)

size vary

heat sensing loreal pits

left lung absent

habitats vary

neurotoxic venom

What family is in Order Rhynchocephalia?

Sphenodontidae

Characteristics of family sphenodontidae

1 species: tuatara

diapsid

ectothermy

oviparous

What suborder of Squamata has the most species?

Larcertilia

Characteristics of order squamata

monophyletic

paired copulatory organs

Jacobson’s organ

true egg tooth

Family Amphisbaenidae characteristics

worm lizards

200 species

worm like and fossorial

limbless or two libs

cone-like head

dist: S. America and parts of Africa

Family Gekkonidae characteristics

wall-climbing geckos

950 species

small, no eyelids

gecko feet, some parthenogenic

Dist: everywhere except N. America and Europe

Family Scincidae characteristics

skinks

1500 species

small, overlapping scales

limb reduction

con-shaped head

Family Teiidae characteristics

whiptail lizards, tegus

150 species

small, ventral scales rectangular in rows

forked tongues

tail autonomous

terrestrial and some parthenogenic

N. and S. America

Family Helodermatidae characteristics

Gila monster, beaded lizard

small, venom glands, broad and heavy bodied

well developed limbs

burrows, arid env.

can eat prey whole

small parts of central america

Family Anguidae characteristics

alligator lizard, glass lizard

66 species

small, limbed or limbless

tail longer than body

non-overlapping scales

osteoderms under scales

ventrolateral fold (helped with breathing)

N. America, S. America, Europe

Family Iguanidae Characteristics

Iguanas and chuckwallas

38 species

large

dorsal spines on back, dewlap on neck, stocky build

oviparous

mostly central and S. America

Family Phrynosomatidae characteristics

N. American spiny lizards

136 species

small-medium size, stocky, scales rough

dominant in N. America

oviparous

When did crocodilian line emerge? When did bird-line emerge?

250 mya; 245 mya

In what period were synapsids and amphibians dominant?

Permian

What happened during triassic/Jurassic mass extinction event?

large synapsids went extinct, radiation of dinos

when was diversification of archosaurs

Triassic

What is archosauria considered and what lineages does it include?

It is monophyletic and includes Pseudosuchia (crocodiles and non-avian archosaurs) and Avemetatarsalia (aves, dinos, pterosaures)

Characteristics of thecodontia

antorbital fenestra

thecodont dentition (in the jaw)

Crocodile like

not useful taxonomic group (paraphyletic)

Characteristics of Order Crocodilia

Gharials, alligators, caimans, crocodiles

thecodonts

poikilothermic

oviparous

4 chambered heart

Ambush predators (eyes on top of head, earflaps allow for hearing under water)

polygynous mating system- elaborate courtship

females parental care

What are osteoderms?

specialized bony plates based in dermis

provides protection and aids in heat exchange

covered by scutes

Family Crocodylidae characteristics

crocodiles and dward crocodiles

2.5m-7m

long, broad jaw

fourth tooth is seen

salt glands

mound builders with parental care

Family alligatoridae characteristics

alligators and caimans

long, broad jaws

all teeth are in mouth

no salt glands

surface of tongue is keratinized

Subfamily alligatorinae characteristics

2-4 m

very broad snout

freshwater

only crocodilian that lives in temperate regions

burrows and wallows

Subfamily Caimaninae characteristics

1.7-5 m

longer, sharper teeth

Family Gavialidae characteristics

4-6.5 m

very long, narrow jaws

all teeth protrude

nests along stream banks, nest guarding