What is the largest known plesiosaur?
The largest long-necked plesiosaur is the Late Cretaceous Elasmosaurus. It reached a length of 13 meters, have of which was taken up by the neck. This genus had the most number of cervical (neck) vertebrae of any animal, living or extinct: 76. The largest pliosaur is possibly Pliosaurus. A jaw which may belong to an individual of this genus measures over 3 meters, which would give a projected body length of 15 meters. Meantime, isolated teeth and vertebrae found in the Oxford Clay of England may have come from an animal over 20 meters long. I was told that my previous reference, Kronosaurus, another denizen of the Late Cretaceous seas found in Australia, had been reconstructed with its 12 meter length exaggerated.
