Lizard
Lizard, common name for certain reptiles in the order that also contains snakes, amphisbaenians ( Worm Lizard ), and the extinct mosasaurs . Lizards constitute the largest living group of reptiles, with more than 4,300 species in a wide variety of shapes and sizes. Although lizards may resemble salamanders and other amphibians, they differ in that lizards have dry scaly skin, and most have clawed feet and external ear openings. Most lizards are small, with four legs and a long tail that in many species is fragile and easily broken but will regenerate; the tail of such arboreal species as the chameleon is adapted for grasping branches. The legs of some lizards are greatly shortened, or vestigial, making animals such as the glass lizard or slowworm snakelike in appearance; they are distinguished from true snakes by their movable eyelids and by differences in the structure of the skull bones, especially those of the lower jaw. The bones of the two halves of a lizard’s lower jaw are fir...