BIO 370 — Vertebrate Zoology
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Vertebrate Diversity
Class Reptilia — Reptiles

(Click on any image for larger version)

Amniote Characteristics

  • Amniotic egg
  • Keratinized, waterproof epidermis
  • Claws and other elaborations of epidermis
  • Costal lung ventilation
  • Heart has partially or completely divided ventricle
  • Specialized axis (2nd vertebra)

Reptilia Characteristics

  • Ectothermy
  • Skin typically covered in scales
  • Typically move by lateral undulations of body
  • Heart 3-chambered or with ability to bypass lungs
  • Taxonomic note: Reptilia (as used here) is a paraphyletic group
See also
Reptile Anatomy page

Order Testudines — Turtles

    Characteristics
    • Anaspid skull with posterior emarginations
    • Shell formed from pectoral girdle, ribs, dermal plates
    • No teeth: mouth forms horny beak
Pond Slider
Pond Slider, Trachemys scripta (Family Emydidae); a typical semiaquatic pond turtle 		Desert Tortoise
Desert Tortoise, Gopherus agassizii (Family Testudinidae), CA; a fully terrestrial tortoise 		Alligator Snapping Turtle
Alligator Snapping Turtle, Macroclemys temminckii (Family Chelydridae); a stationary bottom-dweller (cryptic suction feeder; note pink worm-like tongue)
Snake-necked Turtle
Common Snake-necked Turtle, Chelodina longicollis (Family Chelidae); a stationary bottom-dweller (strike and gape feeding) 		Spiny Softshell
Spiny Softshell, Trionyx spiniferus (Family Trionychidae); an active chaser 		Loggerhead Turtle
Loggerhead Sea Turtle, Caretta caretta (Family Cheloniidae); a fully aquatic turtle

Order Sphenodontia — Tuataras

    Characteristics
    • Generalized lizard-like body
    • Relatively large-sized
    • Nocturnal
    • Skull not kinetic
    • Two temporal fenestra; lower temporal bar
    • Sometimes placed in Order Rhynchocephalia
Tuatara Skull
Spotted Tuatara skull, Sphenodon punctatus
See also labeled photo. 		Tuatara Drawing
Spotted Tuatara, Sphenodon punctatus
Source: R. A. Lydekker 1896. The Royal Natural History, London. Retrieved from Wikimedia

Order Squamata — Lizards, Snakes, etc.

    Characteristics
    • Generalized tetrapod body plan with sprawling limbs
    • Loss of limbs evolved numerous times
    • Mostly predatory
    • Males have hemi-penes (paired penis)
    • Loss of lower temporal bar
    • Increasing skull kinesis

"Lizards"

  • Paraphyletic: includes all squamates except snakes and amphisbaenians.
  • Most have limbs, but leglessness evolved several times
  • Most have eyelids, external ear openings
  • See also Lizard Skulls page
Tropical House Gecko
Tropical House Gecko, Hemidactylus mabouia (Family Gekkonidae), Kenya; specialized climber on smooth surfaces 		Chamaeleon
Montane Side-striped Chamaeleon, Chamaeleo ellioti (Family Chamaeleonidae), Kenya; specialized climber on narrow branches 		Blue-headed Tree Agama
Blue-headed Tree Agama, Acanthocerus atricollis (Family Agamidae), Kenya; a generalized ambush predator
Side-blotched Lizard
Common Side-blotched Lizard, Uta stansburiana (Family Phrynosomatidae); UT; a generalized ambush insectivore 		Desert Grassland Whiptail
Desert Grassland Whiptail, Aspidoscelis uniparens (Family Teiidae), AZ; an active-searching insectivore 		Nile Monitor
Nile Monitor, Varanus niloticus (Family Varanidae), Kenya; an active-searching predator
Chuckwalla
Common Chuckwalla, Sauromalus obesus (Family Iguanidae), CA; herbivorous 		Regal Horned Lizard
Regal Horned Lizard, Phrynosoma solare (Family Phrynosomatidae), AZ; an ant specialist 		Gila Monster
Gila Monster, Heloderma suspectum (Family Helodermatidae); venomous; specialist nest raider
Western Skink
Western Skink, Plestiodon skiltoniatus, CA (Family Scincidae); semi-fossorial in leaf litter 		Grass Lizard
Highland Grass Lizard, Chamaesaura anguina (Family Cordylidae), Kenya; lives in dense grass 		Forest Limbless Skink
Western Forest Limbless Skink, Feylinia currori (Family Scincidae), Kenya; fossorial

Serpentes (Snakes)

  • Monophyletic
  • Legless, elongate
  • No moveable eyelids
  • No external ear openings
  • Forked tongue
  • See also Snake Skulls page
Lineolate Blind Snake
Lineolate Blind Snake, Typhlops lineolatus (Family Typhlopidae), Kenya; a primitive burrowing snake 		Emerald Tree Boa
Emerald Tree Boa, Corallus caninus (Family Boidae); a primitive snake 		Common Kingsnake
Common Kingsnake, Lampropeltis getulus (Family Colubridae), CA; specialist snake-hunter
California Coachwhip
California Coachwhip, Masticophis lateralis (Family Colubridae), CA; active searcher 		King Cobra
King Cobra, Ophiophagus hannah (Family Elapidae); venomous, front-fanged 		Rhinohorned Viper
Rhinoceros-horned Viper, Bitis nasicornis (Family Viperidae), Kenya; a venomous sit-and-wait predator

Amphisbaenia

  • Legless or with only forelegs
  • Heavy rigid skull with nipping front teeth
  • Skin forms rings
  • Burrowers
Mole Lizard
Mole Lizard, Bipes biporus

Order Crocodylia — Alligators & Crocodiles

    Characteristics
    • Large size; semiaquatic
    • Heavy laterally-compressed tail
    • Elevated nostrils
    • Skin with dermal bony armor
Nile Crocodile
Nile Crocodile, Crocodylus niloticus; Kenya 		Alligator
American Alligator, Alligator mississippiensis; FL 		Gavial
Indian Gavial, Gavialis gangeticus
This page last updated 9 December 2011 by Udo M. Savalli ()
Images and text © Udo M. Savalli. All rights reserved.