Snakes

Along with lizards, snakes are classified in the order Squamata, one of the four living orders of reptiles. The other three are the Crocodilia (crocodiles and alligators), Testudinae (tortoises and turtles), and Rhynchocephalia (the tuatara). Snakes are the most recently evolved of the modern reptiles, first appearing in the fossil record about 120 million years ago. It is thought that snakes evolved from lizard-like creatures that gradually lost their legs, external ears, eyelids, frills, and spines, presumably to facilitate unencumbered burrowing and movement through thick underbrush when foraging for food or fleeing from predators.