Plesiosaur

The plesiosaur was a large aquatic reptile from the Jurassic to the Cretaceous periods (180 million B.C. to 63 million B.C.). The plesiosaur was common in the oceans around North America and Europe. Various plesiosaur types vary from eight to over forty feet long. They had long or short necks, four flippers, and a small tail. Plesiosaurs reproduced by laying eggs in holes they had made on beaches.

Several lake monsters around the world have descriptions resembling plesiosaurs. They include the Loch Ness Monster in Scotland, Champ of Lake Champlain, Nahuelito in Argentina, Ogopogo from British Columbia, and Storsjoodjuret or Storsjödjuret from Sweden.