Leatherback sea turtle

The leatherback sea turtle is the largest of all living sea turtles. It is the fourth largest modern reptile behind three crocodilians.
Adults average in shell length, in total length and weigh . The largest ever found was over from head to tail and weighed . It was found on a beach on the west coast of Wales.
The eggs and young are often eaten by predators, but the adults can defend themselves aggressively. Only the largest sea predators can tackle a leatherback successfully.
Leatherback turtles are one of the deepest diving marine animals. They have been recorded diving to depths as great as .
They are also the fastest-moving reptiles. The 1992 edition of the Guinness Book of World Records lists the leatherback turtle moving at in the water.
Usually, they swim at .
They can live as far north as Alaska and Norway and as far south as the Cape of Good Hope in Africa and the southernmost tip of New Zealand. The leatherback is found in all tropical and subtropical oceans, and it also goes well into the Arctic Circle.
Very little is known about how long they live. Some reports say "30 years or more", while others say "50 years or more".