A TRIP to the dentist could perhaps have saved this mighty Tyrannosaurus rex and many of her peers.
Holes found in the jawbones of 10 T. Rex – including “Sue” at the Field Museum in Chicago (pictured) – may not be battle scars from fighting with rivals as previously thought. The holes are more consistent with parasitic infections that gouged holes up to 5 centimetres wide in the bone, says Ewan Wolff at the University of Wisconsin-Madison.
His team examined 61 T. Rex jawbones and saw the holes in 1 in 6 of them. They say the lesions look like those that Trichomonas gallinae causes in birds – especially birds of prey such as hawks and ospreys (PLoS ONE, vol 4, p e7288).
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“I think it would have been very painful,” says Wolff. “Probably, most of the pain would come from feeding and the back of the throat, so it would have been very difficult to swallow and likely difficult to breathe.” He concludes that the infected animals probably starved to death as a result.
Bite marks leave very specific impressions reflecting the shape of the teeth that make them, so Wolff’s team is confident the holes are not battle scars. But bites may have transmitted infections via saliva: “We do know Tyrannosaurus engaged in face biting,” says Wolff.
So the reputation of the fearsome giants remains intact, even if a tiny parasite and chronic inflammation was all it took to finish some of them off.