Snapping turtles have small shells and sea turtles have very soft shells. Turtles that live on the land and tortoises usually have very hard shells. Turtles with soft shells lack horny plates, but do have leathery skin. Turtles are over 200 million years old. Fossils have been found to prove this.
All turtles are tootheless, but have a sharp-edged beak so that they can eat.
This works ver well, especially for the Alliga tor Snapping Turtle, who can bite off a human finger in a single bite. Turtles also have a good sense of eyesight and smell. They can be sexually distinguished by their plastrons. Males have concave plastrons, while females have flat ones.