When we think of dinosaur deaths, we're usually picturing a giant asteroid hurtling toward Earth, or a raptor ripping an herbivorous species to shreds. But some dinosaurs had much more mundane causes of death, and at least one of them bit the dust courtesy of arthritis.
Researchers at the U.K.'s Bristol University were studying the skeleton of a female pliosaur (that mean-looking cross between a crocodile and a shark pictured above) at the Bristol City Museum and Art Gallery when they discovered signs of a degenerative bone condition in the creature's jaw.
The pliosaur's left jaw joint deteriorated to the point that its lower jaw leaned to one side. The animal kept feeding, as marks on the jawbones reveal, but eventually the bone broke entirely. The 26-foot animal was once capable of ripping other ocean-dwelling dinos to bits, but with a broken jaw (and no orthopedic surgeon handy) it could no longer eat.
"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," said Dr. Judyth Sassoon, who led the pliosaur study. "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."
Professor Mike Benton, who collaborated with Sassoon on the study, noted that modern animals including sperm whales and crocodiles have been shown to suffer from similar conditions. As long as they can eat, they can live with it, but in this pliosaur's case the battle was lost.
So not every dinosaur suffered some spectacular, epic death. Some of them just got old and broke down. Let's just hope these findings aren't part of the plot for Jurassic Park 4.