A 7-foot, 655-pound (and he was considered tiny!) leatherback turtle [1], who was rescued by the New England Aquarium in Boston, was released back into the water this weekend.

An endangered species, the leatherback turtle was discovered last week on a mud flat in Pamet Harbor. Aquarium officials described him as being “near death.” The poor “little” guy was underweight (adult males usually weigh 1,000 pounds), and a large portion of its left flipper was missing due to some kind of trauma.

But thanks to a group of volunteers and veterinarians at the marine animal care center who rescued and treated him for dehydration, shock, and trauma, the leatherback sea turtle was able to regain his strength. (We’re happy to know that he’s now swimming somewhere off the coast of Cape Cod.)

Check out these 5 facts about leatherback turtles.

1. They’re the largest of all sea turtles [2] and one of the largest reptiles on earth.
2. Leatherback sea turtles have been around for over 150 million years. They’re the oldest of all sea turtle species.
3. They’re an endangered species. It’s believed that humans are the main reason for this.
4. Leatherbacks [3] eat twice their body weight in prey every day.
5. These sea turtles do not have a hard shell. Rather, their smooth, leathery skin covers a flexible matrix of bone.

Hold a bake sale fundraiser at your school to adopt an endangered animal. GO [4]