Illness may have killed mighty T-Rex

Mighty Tyrannosaurus Rex may have fallen to trench mouth, paleontologists report Tuesday. In a look at the famous T-Rex, Sue, and her kin, a team led by Ewan Wolff of the University of Wisconsin-Madison and Steven Salisbury of Australia's University of Queensland, pin the blame on an avian ailment for ulcers in the jaws of the King of Dinosaurs. The parasitic microbe bores holes in the jaws of falcons and hawks in patterns identical to holes seen in T-Rex fossils, the team reports in the journal PLoS One.

Paleontologists had earlier suggested Sue suffered from a different infection seen today in cattle. Others said she might have been bitten by other tyrannosaurs, the most common source of trauma seen on their fossilized bones (with head bites found on 44% of adults).

However the cattle infection doesn't afflict non-mammals, and T. Rex bites are distinctive and unlike the jaw holes seen in Sue and her fellows. Instead, "these abnormalities have a strong resemblance to those lesions resulting from an infectious disease known to occur in modern birds called trichomonosis," says the study. "Nearly 15% of the 61 tyrannosaurid individuals examined during this study exhibited trichomonosis-type lesions on the mandible."

Tyrannosaurs may have acquired the disease by eating each other, the researchers suggest. Given their shared heritage with birds, likely suffered the same way as hawks and falcons today, enduring debilitating throat damage. ""The lesions we observe on Sue suggest a very advanced stage of the disease and may even have been the cause of her demise," says Wolff, in a statement. "It is a distinct possibility as it would have made feeding incredibly difficult. You have to have a viable pharynx. Without that, you won't make it for very long, no matter how powerful you are."

By Dan Vergano
Photo: An artist's rendering of a T. rex suffering from a trichomonosis-like disease, a parasitic infection caused by a protozoan, a single-celled organism that infects the mouth and throat and may have caused the animal to starve to death. (Chris Glen, University of Queensland)