Some cryptozoologists have long considered that the Loch Ness Monster could be related to a plesiosaur—an aquatic reptile with a long neck and flippers that lived more than 60 million years ago. But one strike against that theory is that plesiosaurs were thought to have been sea creatures and wouldn't be at home in the freshwater of Loch Ness. Now though, scientists report the discovery of plesiosaur fossils in the remains of a 100-million-year-old river system in Morocco's Sahara Desert. The researchers from the University of Bath, University of Portsmouth, and Université Hassan II identified bones and teeth from three-meter long adult plesiosaurs and a 1.5 meter-long baby plesiosaur. From the University of Bath:
These fossils suggest the plesiosaurs were adapted to tolerate freshwater, possibly even spending their lives there, like today's river dolphins[…]
But what does this all mean for the Loch Ness Monster? On one level, it's plausible. Plesiosaurs weren't confined to the seas, they did inhabit freshwater. But the fossil record also suggests that after almost a hundred and fifty million years, the last plesiosaurs finally died out at the same time as the dinosaurs, 66 million years ago.