Dinosaur-like sea reptile suffered from arthritis too

Brussels, May 16 (IANS) Scientists found signs of a degenerative condition similar to human arthritis in the jaw of a pliosaur, a dinosaur-like ancient sea reptile that lived 150 million years ago.

Pliosaurs were probably pursuit or ambush predators, feeding on fish, squid and other marine reptiles but would also have been capable of scavenging.

Bristol University scientists studied a giant specimen of the pliosaur Pliosaurus dating from the Upper Jurassic. Found in Westbury, Wiltshire, it has been kept since its discovery in the collections of the Bristol City Museum and Art Gallery.

The eight metre-long pliosaur was a terrifying creature with a large, crocodile-like head, a short neck, whale-like body and four powerful flippers to propel it through water in pursuit of prey, according to a Bristol statement.

With its huge jaws and 20 cm long teeth, it would have been capable of ripping most other marine reptiles or dinosaurs to pieces, but this particular individual was the unfortunate victim of an arthritis-like disease.

Bristol's Judyth Sassoon, was fascinated by the specimen when she saw it in the museum's collections and studied it for her M.Sc research project. She soon noticed that it had the signs of a degenerative condition similar to human arthritis, that had eroded its left jaw joint, displacing the lower jaw to one side.

This animal evidently lived with a crooked jaw for many years, because there are marks on the bone of the lower jaw where the teeth from the upper jaw impacted on the bone during feeding. Clearly, the animal was still able to hunt in spite of its unfortunate condition.

Sassoon said: "In the same way that aging humans develop arthritic hips, this old lady developed an arthritic jaw, and survived with her disability for some time. But an unhealed fracture on the jaw indicates that at some time, the jaw weakened and eventually broke. With a broken jaw, the pliosaur would not have been able to feed and that final accident probably led to her demise."