Tortoise, turtle, terrapin. Which one is which and how can you tell? If you look at the shape of a turtle’s shell and its feet and legs, it can tell you a lot about how the turtle lives. The Eastern box turtle is considered a land turtle. It has a domed shell, and its toes are only slightly webbed, which tells you it doesn’t spend a lot of time swimming. Though it likes to be near water such as a pond or stream, the Eastern box turtle lives in moist, open forested areas and marshy meadows.

Freshwater turtles that spend most of their lives in the water have flatter shells, thinner legs, and webbing between their toes. All these characteristics help them to be excellent swimmers.

Sea turtles live their whole lives in the water except for the short time they spend crossing the beach to the ocean right after they hatch. Males never leave the water again after this, and females only come onto the beach to lay their eggs. Not surprisingly, they too have flat shells made for swimming. Instead of legs and toes, however, sea turtles have flippers that let them almost “fly” through the sea.

Tortoises are obviously land-dwellers. They have high domed shells, thick, chunky legs and feet without any webbing. As long as they have fresh water to drink, they may live far from a lake or pond.

There is only one terrapin in the United States: the diamondback terrapin. This turtle is the only species that lives in brackish water, or water that is part fresh and part salt water. It spends a lot of time by and in the water, so it has a flatter shell and webbed toes.

There are two parts to every turtle’s shell: the carapace and the plastron. The carapace is the shell on the back of the turtle, and the plastron is the shell on its belly. The reason that the box turtle has its name is because it can pull its head and legs inside its shell and then “close” its hinged plastron, making itself into a box. This protects the turtle from almost any predator.