Sauria
- Iguanidae
New World lizards.
- Agamidae
An Old World reptile family of Sauria.
- Scincidae
Skinks.
- Anguidae
Alligator lizards.
- Teiidae
Whiptails; etc.
- Gekkonidae
Geckos.
- Helodermatidae
Only known venomous lizards.
- Lacertidae
Old World lizards.
- Chamaeleontidae
Old World chameleons; in some classifications they are considered a superfamily...
- Pygopodidae
Australian and Tasmanian lizards.
- Xantusiidae
Night lizards.
- Xenosauridae
Monotypic family of Mexican lizards.
- Anniellidae
Legless lizards.
- Lanthanotidae
Stout-bodied lizards.
- Varanidae
Monitor lizards.
- Amphisbaenidae
Worm lizards.
Serpentes
- Colubridae
Nonvenomous snakes; about two-thirds of all living species.
- Elapidae
Cobras; kraits; mambas; coral snakes; Australian taipan and tiger snakes.
- Crotalidae
New World vipers: pit vipers.
- Boidae
Boas and pythons.
- Viperidae
Old World vipers.
- Leptotyphlopidae
Blind snakes.
- Hydrophidae
Sea snakes.
- Typhlopidae
Blind snakes.
Chelonia
- Emydidae
Box and water turtles.
- Testudinidae
Land tortoises.
- Cheloniidae
Green turtles; hawksbills.
- Chelydridae
Snapping turtles.
- Kinosternidae
Mud turtles; musk turtles.
- Trionychidae
Soft-shelled turtles.
- Dermochelyidae
Sea turtles.
Crocodylia
- Crocodylidae
True crocodiles.
- Alligatoridae
Alligators; caimans.
- Gavialidae
Gavials.
Euronithopoda
- Hadrosauridae
Duck-billed dinosaurs; upper Cretaceous.
- Iguanodontidae
Iguanodons.
Also contains
- Dromaeosauridae
Swift-running bipedal dinosaurs.
- Pythoninae
Old World boas: pythons; in some classifications considered a separate family from B...
- Titanosauridae
Herbivorous dinosaurs of the Cretaceous.
- Ichthyosauridae
Later ichthyosaurs of the Jurassic and Cretaceous; widely distributed in both h...
- Megalosauridae
Megalosaurs.
- Edaphosauridae
A family of reptiles of the order Pelycosauria.
- Pterodactylidae
A reptile family in the order Pterosauria.
- Pythonidae
In some classifications a family separate from Boidae comprising Old World boas.
- Ceratopsidae
American ceratopsian dinosaurs.