Reptiles can be easily recognized by their horny or scaly skin. The class Reptilia has 4 orders: Rhynchocephalia, in which the sole species is the tuatara (a reptile that looks like an iguana but does not belong to the iguana family and is found only on islands off New Zealand); Crocodilia, which includes alligators, caimans, crocodiles, and gavials (a crocodile-like reptile native to India, Borneo, and Sumatra); Chelonia, which contains tortoises and turtles; and Squamata, which contains lizards and snakes.

Last full review/revision July 2011 by Roger J. Klingenberg, DVM