Dinosaur Arthritis Existed 150 Million Years Ago

Palaeontologists from Bristol University, England have discovered that a degenerative condition similar to human arthritis existed 150 million years ago when the dinosaurs roamed the earth.

Giant Marine Reptile Jaw Bone Discovered

A fossilized jaw bone from a giant Pliosaurus dating back to the Upper Jurassic period was discovered in Westbury, Wiltshire in England. Research recently published in the International Palaeontological Journal shows just how this ancient reptile was affected by the chronic arthritis like disease.

Pliosaurus was a strange looking ancient sea reptile that lived 150 million years ago. It measured eight meters long and had a large crocodile-like head on a whale-like body with a short neck, four powerful flippers and a huge jaw which held 8 inch long teeth.

These giant marine predators, which would have lived in the seas in what is now recognized as England and mainland Europe (Kimmeridge Clay Formation), were at the top of the food chain. Though able to rip most other reptiles and dinosaurs living at the time to pieces with their sharp teeth, it is thought they would have mostly eaten fish, squid and other marine reptiles that they would scavenge.

Dinosaur Arthritis Deduced From Marine Reptile Bone

Dr Judyth Sassoon of Bristol University, England first saw the Pliosaurus specimen at the City Museum and Art Gallery of Bristol and was fascinated by it. She, along with her team of researchers, studied the fossilized skeleton in depth and noticed that it showed signs of a condition similar to arthritis in humans through its eroded left jaw joint which had displaced the lower jaw to one side.

Old Lady Pliosaurus had “Dinosaur Arthritis”

It is thought that this Pliosaurus specimen was an ‘old lady’ who developed the arthritis-like disease due to old age just as humans do. The large size of the fossilized skeleton with fused bones suggests maturity in this ancient marine reptile whilst the deduction of it being female is due to its skull crest being quite low.

Marks on the bone of the lower jaw where the upper jaw would have impacted when the Pliosaurus ate, show that this creature suffered with the chronic condition for many years but was able to carry on eating and living, in the same way that humans can live with the painful condition.

An Arthritic Jaw Eventually Killed this Pliosaurus

Palaeontologists can see that an unhealed fracture on the jaw indicates that the arthritic-like jaw would have eventually weakened and then broken and prevented the Pliosaurus from eating, leading to her death.

Modern Day Animals With “Dinosaur Arthritis”

It is known that modern-day crocodiles and sperm whales suffer with a similar condition to this “dinosaur arthritis” in the same way but are able to carry on living for years so long as they are able to carry on feeding just like the Pliosaurus did.

The Significance of This Discovery

This discovery is the first time that an arthritis-like disease has been discovered in Jurassic reptiles, though palaeontologists have discovered two fossils that show arthritis in the ankle joints of Iguandon – A 9 meter long and 5 meter tall Ornithopod that lived during the early Cretaceous period.

No Evidence of Arthritis in Theropods or Sauropods

Though the condition has been found in one Pliosaur and two individual Iguandon specimens, so far palaeontologists have not seen signs of this “dinosaur arthritis” in theropods, sauropods, ankylosaurs, hadrosaurs or stegosaurs.