Which marine reptile is the largest living turtle?

The leatherback sea turtle is the largest living turtle.

Leatherbacks can reach about 2 metres in total length and weigh more than 900 kilograms, making them much larger than other living sea turtles. Their scientific name is Dermochelys coriacea, and they are the only living members of the family Dermochelyidae.

Unlike other modern sea turtles, leatherbacks do not have a hard, bony shell covered by large scutes. Instead, their back has a flexible, leathery covering over a layer of small bones. Seven prominent ridges run along the carapace, helping give the animal its streamlined shape.

Leatherbacks are specialized for eating jellyfish and other soft-bodied prey. They can travel across entire ocean basins and have been recorded in colder waters because their large size, thick tissue and adaptations for heat retention help them maintain body temperature better than many other reptiles. They still come ashore to lay eggs, usually on sandy tropical or subtropical beaches.