These are all horny-shelled, four legged reptiles. The tortoise lives on land and has stubby legs. It ranges in size from the small tortoises that are kept as pets to the giant tortoises of the Galapagos Islands. Terrapins live in fresh water and tidal water and are usually found in the United States. They have slightly webbed feet.
Turtles live in the sea and their legs are like flippers. The females crawl up the sandy shore to lay their eggs. The leatherback is the largest of the turtles.