T. REX’S TERMINAL TOOTHACHE

The T. rex was the king of the Late Cretaceous period. It boasted a mouthful of banana-sized teeth and a biting force of 3,500 kilograms – that’s like the impact of three small cars. But these champion chompers were also the apex predator’s weak spot. “Some of the world’s most famous T. rex specimens have these holes in their jaws,” says Dr Steve Salisbury from the University of Queensland. “Some specimens look like Swiss cheese.” Working with a small team, Salisbury examined over 60 T. rex fossils. This included Sue, one of the best preserved skeletons, which is on display at Chicago’s Field Museum.

“We now believe that these holes are caused by an infectious disease called trichomonosis,” Salisbury says. This is an illness caused by microscopic parasites. Many pigeons carry it today but are immune. But hawks and falcons that eat pigeons can get very sick, developing lesions in their lower beaks. It’s possible that T. rex caught the infection from their prey too. But the fierce theropods were also known to fight among themselves. “We don’t think it’s a coincidence that a significant number of adult tyrannosaur specimens show both face-biting marks and evidence of a trichomoniasis-like disease,” Salisbury says. “Fighting, and specifically head-biting, would have been an ideal mechanism for spreading the disease among tyrannosaurs.” However it was caught, the infection would have meant a slow, painful death. It would have made it harder and harder for the creature to eat until it starved.