Plesiosaurus was a prehistoric sea monster that lived during the Mesozoic Era, approximately 200 million years ago. It was a large marine reptile with a long neck, four paddle-like flippers, and a short tail. It was a carniv
Plesiosaurus is a genus of extinct, large marine sauropterygian reptile that lived during the Early Jurassic. It is known by nearly complete skeletons from the Lias of England. Measuring around 3.5 m (11 ft) long, it is distinguishable by its small head, long and slender neck, broad turtle-like body, a short tail, and two pairs of large, elongated paddles. It lends its name to the order Plesiosauria, of which it is an early, but fairly typical member. It contains only one species, the type, Plesiosaurus dolichodeirus. Other species once assigned to this genus, including P. brachypterygius, P. guilielmiimperatoris, and P. tournemirensis have been reassigned to new genera, such as Hydrorion, Seeleyosaurus and Microcleidus.