<img alt=“t rex head hole.jpg” src=“http://blogs.nature.com/news/thegreatbeyond/t%20rex%20head%20hole.jpg” width=“400” height=“257” align=“right” border=0 hspace=“10px”/>Many Tyrannosaurus rex may have been laid low by a single celled parasite that is still taking down modern birds.
Many tyrannosaurid fossils have multiple smooth holes in their mandibles. These have generally been attributed to either bacterial bone infection or bite wounds.
Now a study published in PLOS One instead points the finger at the trichomonosis parasite. By comparing the lesions seen in fossil dinos to those caused by modern bird maladies and crocodile pox the research team concludes tyrannosaurs were commonly infected with a trichomonas type protozoa.
The population probably became infected through consumption of infected prey, or even through cannibalism, write Ewan Wolff, of the University of Wisconsin, Madison, and colleagues.
Perhaps the most famous victim may have been ‘Sue’, the huge T. rex now on display at the Field Museum in Chicago. “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 (press release).
“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.”
Field Museum palaeontologist Peter Makovicky told the Chicago Tribune. “It … reinforces what I and many others thought, that [the jawbone holes] were the result of some kind of pathogen.
He adds, “The problem with … making a diagnosis of an animal that old is that we know she had many things going wrong with her health. [Sue] was old and beat up, with a large lesion on her left leg that may have slowed her. She could have died simply of old age or had been so weakened by age or injury that some other disease took over.”
Image: artist’s impression of a T. rex suffering from a trichomonosis / Chris Glen, University of Queensland