Lizard

lizard, (suborder Sauria), any of more than 5,500 species of reptiles belonging in the order Squamata (which also includes snakes, suborder Serpentes). Lizards are scaly-skinned reptiles that are usually distinguished from snakes by the possession of legs, movable eyelids, and external ear openings. However, some traditional (that is, non-snake) lizards lack one or more of these features. For example, limb degeneration and loss has occurred in glass lizards (Ophisaurus) and other lizard groups. Movable eyelids have been lost in some geckos, skinks, and night lizards. External ear openings have disappeared in some species in the genera Holbrookia and Cophosaurus. Most of the living species of lizards inhabit warm regions, but some are found near the Arctic Circle in Eurasia and others range to the southern tip of South America.

Snakes arose from lizards and are thus considered to be a highly specialized group of limbless lizards. In addition to those traits they have in common with non-snake lizards, snakes are often separated from other lizards in popular literature because they share a set of unique traits that are relatively easy to observe. For a full description of snakes, see snake.