The diamondback terrapin (Malaclemys terrapin) or simply terrapin, is a species of turtle native to the brackish coastal swamps of the eastern and southern United States. It belongs to the monotypic genus, Malaclemys. It has one of the largest ranges of all turtles in North America, stretching as far south as Florida Keys and as far north as Cape Cod.The name "terrapin" is derived from the Algonquian word torope. It applies to Malaclemys terrapin in both British English and American English.