Researchers have found traces of painful arthritis in the jaw of a pliosaur, a large sea monster that lived nearly 150 million years ago.
The team from Bristol University examined the fossilized remains of the iconic specimen found in Westbury, Wiltshire.
Erosion of its jaw joints suggests the sea reptile endured joint pain, swelling and stiffness linked with the disease.
The discovery is the first case of a giant marine reptile known to have suffered from the degenerative condition.
Dr Judyth Sassoon, a University of Bristol scientist who studied the skeleton and led the project said, “When I saw it for the first time three years ago, I was instantly fascinated by some of the unusual markings on the lower and upper jaws."
"At the time the fossil still needed to be extracted from the clay matrix in which it was discovered, and the museum staff kindly helped with that daunting task. Once the fossil was cleaned up, this pliosaur’s unique life story started to make sense.”
“The disease led to a misalignment of jaws, the lower jaw being deviated to one side. This is clearly indicated by tooth marks from the upper jaw impinging on the bone of the lower jaw and, similarly, a tooth from the lower jaw causing an infection in the tooth socket of the upper jaw.”—Judyth Sassoon
Examination of incredible jaw
Pilosaurs lived in the Jurassic and Cretaceous periods and were the most terrifying predators which ruled the oceans of the world with great ease.
The amazing 26 ft long fearsome predator had a massive crocodile-like head, a short neck, whale-like body and four powerful flippers that allowed this powerful creature to propel through the water.
The pliosaur identified as female because of low skull crest was at a mature age which was evident by its large size and fused skull bones.
The study of her incredible jaw bone complete with gigantic razor sharp teeth showed that the massive sea creature had spent her twilight years battling progressive arthritis.
The scientists noted that the disease had led to the erosion of the left jaw which had displaced the lower jaw to one side.
Sassoon explained, “The disease led to a misalignment of jaws, the lower jaw being deviated to one side. This is clearly indicated by tooth marks from the upper jaw impinging on the bone of the lower jaw and, similarly, a tooth from the lower jaw causing an infection in the tooth socket of the upper jaw.”
Pliosaur lived with crooked bite for years
Though hampered by the painful condition, the sea monster continued to prey on fish, squid and other marine reptiles.
According to experts, marks on its lower jaw suggest the fearsome predator lived for some time with a slightly crooked mouth.
Sassoon stated, "In the same way that ageing 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 shows 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."
The research was published today in the international journal Palaeontology.