Elasmosaurus (name meaning "Thin-Plated Lizard") is a genus of plesiosaur that originated during the Late Cretaceous period in what is now North America. Distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles, Elasmosaurus is the largest and most famous plesiosaur.
Thought to have been extinct for 65 million years, there are still some that remain alive on Primeval Island.