Archelon

Archelon ichyros is an extinct species of sea turtle from the late Cretaceous period 80.21 to 74.21 mya. Archelon is the largest sea turtle that ever lived with a shell of about 4 metres across it was strict carnivore and used it's sharp beak to eat squid, fish and jellies. Archelon was once thought to be closely related to the leatherback sea turtle but now we know it was far different. Archelon's giant shell would be very defeseful against small sharks and plesiosaurs but it was no match for giant sea creatures like Plotosaurus and the Ginsu shark.