The ancient giant turtle, the largest sea turtle in history. Also known as the Emperor Turtle, Ancient Turtle, Terror Turtle, Mock Turtle, or Ancestral Turtle, it is an extinct genus of sea turtle and the largest sea turtle in history. It is similar to the current leatherback turtles, both of which live in the sea. The body shape is very similar to that of today's sea turtles, with a beak that has huge biting power, and may feed on animals such as squid. The first fossil of the ancient giant turtle genus was discovered in 1895, and this fossil is very famous. On the one hand, it is huge, and on the other hand, it lacks a right hind foot, which is likely to have been bitten off by some giant predator.