Even ancient prehistoric creatures suffered the ravages of old age, as scientists studying the remains of an ancient Loch Ness Monster-style creature known as a pliosaur showed evidence of arthritis in its jaw bones.

The mouth of this ancient Loch Ness Monster was so large that a human being could fit inside it.

With teeth 8 inches long and huge jaws more than three feet long, the pliosaur relied on its massive jaw muscles to rip into its food sources.

Related: Brand New Loch Ness Monster Photo Appears On MSNBC

Evidence of a disease resembling arthritis eventually led this dinosaur to suffer a broken jaw bone, which in turn affected the animal’s ability to kill its prey and chew its food.

Scientists speculate that the ancient Loch Ness creature may have lived for years in pain with an arthritically twisted jaw prior to losing its ability to chew and eventually dying from hunger before it could be attacked or eaten by other, stronger pliosaurs.

Scientists Discover Ancient Loch Ness Monsters Suffered Arthritis

Scientists Discover Ancient Loch Ness Monsters Suffered Arthritis