Chelonia

An order of Reptiles, called the "Crown Group". It's distinctive characteristic is that part of its vertebrae, ribs, and sternum unite with its dermal plates so as to form a firm shell. The jaws are covered by a horny beak. Testudines, today’s turtles, pushed many other groups to the side during it's evolution, however, to a certain extent, the Chelonia are still going strong.

Also, the genus of turtle to which the Green Sea Turtle belongs.