Terrapin is an Algonquian Indian word for edible turtles that live in fresh or brackish water. Water is brackish if it contains some salt, but it is not as salty as ocean water. Diamondbacks are the only turtles in the world that live exclusively in brackish water. In Maryland, they live in the salt marshes of the Chesapeake and Chincoteague Bays where they feed on sof t clams and razor clams. They also eat snails, crabs, shrimp and even the roots and shoots of marsh plants.
Terrapins are reptiles, as are all turtles.
Snakes, lizards and crocodiles are other reptiles. Turtles are the only reptiles that do not have teeth. Instead they have strong horny beaks. They are also the only reptiles with hard shells. The top shell is called the carapace and the bottom shell is called the plastron.