A diamondback terrapin, Malaclemys terrapin, crosses Great Bay Boulevard in Tuckerton, New Jersey, USA. This turtle is named for the diamond patterns on its top shell. The diamondback terrapin's range is along the Atlantic and Gulf coasts, from Cape Cod to Texas. It is believed to be the only turtle in the world that lives exclusively in brackish-water areas. In these areas, such as tidal marshes, estuaries, and lagoons, the water contains some salt, but it is not as salty as the ocean.