Archelon, the largest extinct turtle to ever Exist
Archelon ischyros is an extinct marine turtle from the Late Cretaceous, and is the largest turtle ever to have been discovered, with the biggest specimen measuring 5 m (16 ft) from head to tail and 2,200 kg (4,900 lb) in body mass.
Archelon had a leathery carapace instead of the hard shell common on sea turtles.