Turtle is the only reptile with a shell. There are about 240 species of turtles.
Some turtles live only on land, but others spend almost their entire life in the sea.
Still other species dwell mainly in fresh water or live about equally on land and in fresh water. Tortoise is a turtle that lives only on land. Tortoises have stumpy hind legs like those of an elephant, quite different from the flippers and webbed feet of water turtles. During the winter, they sleep in holes that they dig. They eat plants, and some live more than a hundred years.