BIO 370 — Vertebrate Zoology
 Go To: Udo Savalli | BIO 370 |

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 Rhynchocephalia — Tuataras

    Characteristics
    • Generalized lizard-like body
    • Relatively large-sized
    • Nocturnal
    • Skull not kinetic
    • Two temporal fenestra; lower temporal bar
    • Sometimes placed in Order Sphenodontia
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
Medit. House Gecko
Mediterranean House Gecko, Hemidactylus turcicus (Family Gekkonidae), AZ; specialized climber on smooth surfaces 		Chamaeleon
Montane Side-striped Chameleon, Trioceros ellioti (Family Chamaeleonidae), Kenya; specialized climber on narrow branches 		Blue-headed Tree Agama
Gregory's Blue-headed Agama, Acanthocerus gregorii (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 		Western Skink
Egyptian Spiny-tailed Agamas, Uromastyx aegyptia (Family Agamidae); herbivorous; thick tail stores nutrients and provides defense when in burrow 		Regal Horned Lizard
Regal Horned Lizard, Phrynosoma solare (Family Phrynosomatidae), AZ; an ant specialist
Gila Monster
Gila Monster, Heloderma suspectum (Family Helodermatidae); venomous; fossorial; conserves energy by moving little 		Caiman Lizard
Caiman Lizard, Dracaena sp. (Family Teiidae); a snail-eating specialist 		Western Skink
Western Skink, Plestiodon skiltoniatus, CA (Family Scincidae); semi-fossorial in leaf litter
Western Skink
Sandfish, Scincus scincus (Family Scincidae); fossorial in loose sand 		Fringetoed Lizard
Mojave Fringe-toed Lizard, Uma scoparia, CA (Family Phyrnosomatidae), a sand-dune specialist 		Serpentiform Skink
Western Serpentiform Skink, Eumecia anchietae, CA (Family Scincidae), an elongated, snake-like grassland lizard
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 		Mole Lizard
Mole Lizard, Bipes biporus; an Amphisbaenian, a group of specialized fossorial lizards; most are limbless but the species shown here has front legs only.

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 arboreal snake native to S. America; note heat-sensing pits along upper jaw 		Green Tree Python
Green Tree Python, Morelia viridis (Family Pythonidae); a primitive arboreal snake native to SE Asia
Common Kingsnake
Common Kingsnake, Lampropeltis getulus (Family Colubridae), CA; specialist snake-hunter 		Green Mamba
Green Mamba, Dendroaspis angusticeps (Family Elapidae); an arboral 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 		Bushmaster
Bushmaster, Lachesis muta (Family Viperidae); a sit-and-wait predator; note heat sensing pit between eye and naris 		Ringneck Snake
Ring-necked Snake, Diadophis punctatus (Family Colubridae), CA; in defensive pose while excreting foul-smelling feces
SonoranMtKingsnake
Sonoran Mountain Kingsnake, Lampropeltis pyromelana (Family Colubridae), AZ; a harmless snake that resembles a venomous coral snake 		Gopher Snake
Gopher Snake, Pituophis catenifer (Family Colubridae), CA; spreading head and posing to mimic a rattlesnake 		Patch-nosed Snake
Western Patch-nosed Snake, Salvadora hexalepis (Family Colubridae), AZ; a terrestrial active searcher

Order Testudines — Turtles

    Characteristics
    • Anapsid 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
Mojave Desert Tortoise, Gopherus agassizii (Family Testudinidae), CA; a fully terrestrial tortoise 		Box Turtle
Eastern Box Turtle, Terrapene carolina (Family Emydidae), KY; a terrestrial tortoise-like turtle
Snake-necked Turtle
Common Snake-necked Turtle, Chelodina longicollis (Family Chelidae); an aquatic sit-and-wait predator (strike and gape feeding) 		Alligator Snapping Turtle
Alligator Snapping Turtle, Macroclemys temminckii (Family Chelydridae); an aquatic sit-and-wait predator (cryptic suction feeder; note pink worm-like tongue) 		Matamata
Mata Mata, Chelus fimbriatus (Family Chelidae); an aquatic sit-and-wait predator (cryptic suction feeder)
Spiny Softshell
Spiny Softshell, Trionyx spiniferus (Family Trionychidae); an active chaser 		Fly River Turtle
Fly River Turtle, Carettochelys insculpta (Family Carettochelyidae); the only fully aquatic fresh-water turtle 		Loggerhead Turtle
Loggerhead Sea Turtle, Caretta caretta (Family Cheloniidae); a fully aquatic marine turtle

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; Family Crocodylidae 		Alligator
American Alligator, Alligator mississippiensis; FL; Family Alligatoridae 		Gavial
Indian Gharials, Gavialis gangeticus; Family Gavialidae
Freshwater Crocodile
Freshwater Crocodile, Crocodylus johnstoni; Family Crocodylidae 		Caiman
Spectacled Caiman, Caiman crocodilus; Family Alligatoridae 		False Gharial
False Gharial, Tomistoma schlegelii; Family Gavialidae
This page last updated 7 March 2021 by Udo M. Savalli ()
Images and text © Udo M. Savalli. All rights reserved.