have flippers that are permanently outside the shell. 6 All shapes and sizes There are more than 300 different species, and the largest is the leatherback sea turtle. It can grow up to 900kg.

The green turtle is a large, weighty sea turtle with a wide, smooth carapace, or shell. It inhabits tropical and subtropical coastal waters around the world and has been observed clambering onto ...

While all other sea turtles have hard, bony shells, the inky-blue carapace of ... dive to depths of 4,200 feet—deeper than any other turtle—and can stay down for up to 85 minutes.