Plesiosaurus
Plesiosaurus was a fairly typical member of its order, and measured around 3 to 5 metres (10 to 16 ft) in total length. The snout was short, but the jaws were able to open very wide, and had a series of conical teeth in sockets. The neck was quite long, and the short tail was used for steering. Like all plesiosaurs, it used its large paddles to swim.