Fossil discovery suggests the Loch Ness Monster may have once existed

A recent study has found evidence pointing to the possible existence, at one point in time, of the famous Loch Ness Monster.

Scientists from the University of Bath and University of Portsmouth in the U.K., as well as the Université Hassan II in Morocco, published a study last week in the journal Cretaceous Research on the discovery of small plesiosaurs from a 100-million-year-old river system, now part of the Sahara.

According to the study, plesiosaurs were long-necked marine reptiles with small heads and four long flippers that existed during the time of the dinosaurs. They also served as inspiration for the Loch Ness Monster in Scotland.

While previously believed to be marine animals, the study suggests plesiosaurs may have lived in fresh water.

"We don't really know why the plesiosaurs are in fresh water," Nick Longrich, a paleontologist and evolutionary biologist from the University of Bath's Milner Centre for Evolution, said in a press release.

"It's a bit controversial, but who's to say that because we paleontologists have always called them 'marine reptiles,' they had to live in the sea? Lots of marine lineages invaded fresh water."

As for what this means for the existence of the Loch Ness Monster, the researchers say it is "plausible" that the creature existed.

However, they say the fossil record also suggests the last plesiosaurs died at the same time as the dinosaurs -- 66 million years ago.

The fossils mentioned in the study include bones and teeth from three-metre long adults, and an arm bone from a 1.5-metre baby.

"It's scrappy stuff, but isolated bones actually tell us a lot about ancient ecosystems and animals in them. They're so much more common than skeletons, they give you more information to work with," Longrich said.

"The bones and teeth were found scattered and in different localities, not as a skeleton. So each bone and each tooth is a different animal. We have over a dozen animals in this collection."

The researchers say the animals may have lived routinely and fed in fresh water, possibly spending their entire lives there, similar to today's river dolphins.

They say it's also possible plesiosaurs were able to tolerate both fresh and salt water in the same way modern whales can, such as belugas.

The scientists say the teeth also offer additional clues about the animal.

Not only were the teeth lost while the creature was alive, they show heavy wear, similar to the large aquatic dinosaur Spinosaurus found in the same ancient riverbeds.

The heavy wear, the researchers say, implies the plesiosaurs ate the same armoured fish in the river as the Spinosaurus, meaning they spent a lot of time there.

"What amazes me is that the ancient Moroccan river contained so many carnivores all living alongside each other," study co-author David Martill, a professor of paleobiology at the University of Portsmouth, said in the release.

"This was no place to go for a swim."