Reptiles are tetrapod animals in the class Reptilia, comprising today’s turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptileorders, historically combined with that of modern amphibians, is called herpetology.
Reptiles are cold-blooded vertebrates. (Vertebrates have backbones.) They have dry skin covered with scales or bony plates and usually lay soft-shelled eggs.