| Bird disease struck down T. rex|
|The terrifying Tyrannosaurus rex and its close relatives may have suffered from trichomonosis, according to a new study, a potentially life-threatening disease that still exists today.|
Some of the world's most famous T.rex specimens, such as 'Sue' at the Field Museum in Chicago and the specimen at the Carnegie Museum of Natural History in Pittsburgh, have holes in the lower jaw, which is a classic symptom of trichomonosis, say the team of US and Australian researchers.
"The holes in tyrannosaur jaws occur in exactly the same place as in modern birds with trichomonosis," says Ewan Wolff, a paleontologist from the University of Wisconsin-Madison who worked on the study.
"The shape of the holes and the way that they merge into the surrounding bone is very similar in both animals," he says.
Trichomonosis is carried mainly by pigeons, but they are generally immune to the disease. Birds of prey are particularly susceptible to trichomonosis if they eat infected pigeons.
Palaeontologists previously thought the holes in T.rex were caused by tooth gouges or bacterial infections.
But according to the study, which was published on the open-access journal website PLoS ONE, the position and nature of the holes indicate that the dinosaur had a trichomonosis-type disease.
The disease appeared to be quite common in tyrannosaurs and could have been deadly to those that were infected.
"As the parasites take hold in serious infections, lesions form around the jaw and inside the throat, eventually eating away the bone. As the lesions grow, the animal has trouble swallowing food and may eventually starve to death," says Dr Steve Salisbury of the University of Queensland.
Researchers have found no other dinosaurs that had the disease, and believe it was spread between tyrannosaurs by biting or even through cannibalism.