Leatherbacks are the largest turtles on Earth, growing up to seven feet long and exceeding 2,000 pounds. These reptilian relics are the only remaining representatives of a family of turtles that traces its evolutionary roots back more than 100 million years. Once prevalent in every ocean except the Arctic and Antarctic, the leatherback population is rapidly declining in many parts of the world.

While all other sea turtles have hard, bony shells, the inky-blue carapace of the leatherback is somewhat flexible and almost rubbery to the touch. Ridges along the carapace help give it a more hydrodynamic structure. Leatherbacks can dive to depths of 4,200 feet—deeper than any other turtle—and can stay down for up to 85 minutes.

Leatherbacks have the widest