Archelon

Defender
Unlike most modern turtles, Archelon did not have a solid shell, but instead had a skeletal framework supporting a leathery or bony carapace. Other distinguishing features include a pointed tail, a narrow skull, a relatively narrow, high-vaulted shell, and a pronounced overbite. The live weight of an Archelon ischyros is estimated at more than 2200 kg (4,850 lb).