All turtle species are refered to under the title of Chelonia. There is no singular general name for the cheloniae. They are refered to as a turtle if they simply have a shell and, more specifically as a tortiose if they are among the slow moving terrestrial species. All turtles are members of the scientific class Reptilia.
Reptiles also have scaly skin and a three chambered heart.
They breathe air with lungs, even marine species of turtles, proving them to be amazing swimmers and incredible divers. Turtles are also all members of the order Testudines . Testudines are divided into three suborders. In this way, the leatherback gives us a possible tie to the ancient turtle heritage due to its differences from other species. The leatherback is the largest species of sea turtle and the only one whose backbone is not attached directly to the inside of its shell.