T. Rex 'Sue' was killed by lowly parasite, indicates new evidence

Washington, September 30 (ANI): In a new study, scientists have found evidence that 'Sue', the mighty Tyrannosaurus rex whose fossilized remains are a star attraction of the Field Museum in Chicago, was felled in more mundane fashion by a lowly parasite that still afflicts modern birds.

The study was conducted by an international team of researchers led by Ewan D.S. Wolff of the University of Wisconsin-Madison and Steven W. Salisbury of the University of Queensland, Australia.

The researchers pinned the demise of Sue and other tyrannosaurs with similar scars on an avian parasitic infection called trichomonosis, caused by a single-celled parasite that causes similar pathologies on the mandibles of modern birds, raptors in particular.

It is possible the infection in her throat and mouth may have been so acute that the 42-foot-long, 7-ton dinosaur starved to death, according to Wolff, a vertebrate paleontologist and a third-year student at the UW-Madison School of Veterinary Medicine.

The focus of the new study was a survey of lesions on the jaws of Sue and nine other tyrannosaur specimens.

The lesions had previously been attributed to bite wounds or, possibly, a bacterial infection.

"What drew my attention to trichomonosis as a potential candidate for these mysterious lesions on the jaws of tyrannosaurs is the manifestation of the effects of the disease in (bird) raptors," explained Wolff.

"When we started looking at trichomonosis in greater depth, there was a story that matched some lines of evidence for transmission of the disease in tyrannosaurs," he added.

The pattern of lesions, according to Wolff, closely matches the holes in the jaws of tyrannosaurs and occurs in the same anatomical location.

The scars of combat among tyrannosaurs and other dinosaurs, are not uncommon, but differ notably from the lesions that are the focus of the current study.

The holes caused by trichomonosis tend to be neat and have relatively smooth edges, while bite marks are often messy, and they scar and puncture bone in ways that are not readily comparable.

Tyrannosaurs, notes Wolff, are known to have been gregarious, intermingling, fighting amongst themselves, and sometimes eating one another.

"Transmission of the parasite may have been through salivary contact or cannibalism, noting that there is no known evidence of trichomonosis in other dinosaurs," said Wolff.

"This leads us to suspect that tyrannosaurs might have been the source of the disease and its transmission in its environment," he added.(ANI)