9781422283479

People (mammals) share some traits with reptiles. We both have a bony skeleton, a brain and heart, lungs, and a stomach and intestines to digest food. But the similarities end there! Reptiles come in many different shapes and sizes. Turtles have an unusual shape. Their shell is part of their skeleton. Snakes and some lizards are different from other reptiles, too, because they have no legs. But most reptiles have a long, slim body and a tail, with four short legs that spread sideways to take their weight.

A reptile’s scales are made of a tough material called keratin. Your fingernails are made of the same stuff. The scales form a barrier, like a suit of armor. But unlike armor, the reptile’s skin bends, so it can move—and some move very quickly.

All reptiles shed or lose their old scales from time to time. This is called molting.

Some reptiles have extra armor. The thorny devil found in the American desert is a lizard with sharp spikes on its body to keep enemies away.

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