Tyrannosaurs were violent cannibals

Friday, April 10, 2015

Artists reconstruction of one Daspletosaurus feeding on another. (Tuomas Koivurinne )

Remains of a mutilated dinosaur victim provide strong evidence for what has long been suspected - Tyrannosaurus rex and his kin were violent animals that also practiced cannibalism.
The remains, described in the latest issue of the journal PeerJ, are of the large carnivorous tyrannosaur Daspletosaurus, which suffered numerous injuries during its lifetime and was partially eaten after it died.

Palaeontologists believe that members of Daspletosaurus' own species inflicted all of the damage.

"This animal clearly had a tough life suffering numerous injuries across the head including some that must have been quite nasty," says lead author David Hone from Queen Mary University of London.

"The most likely candidate to have done this is another member of the same species, suggesting some serious fights between these animals during their lives," he adds.

Daspletosaurus lived around 77 million years ago in North America. The victim studied by the researchers hailed from what is now Alberta, Canada. It was an older teenager when it bit the dust, so it hadn't grown to full size yet. Still, this was a large animal. At death it measured about 6 metres long and weighed approximately 500 kilograms.

Analysis of this dinosaur's skull uncovered numerous injuries that had previously healed.

Although not all of the injuries can be attributed to bites, several are close in shape to the teeth of tyrannosaurs, Hone says. One bite to the back of the head had broken off part of the skull and left a circular tooth-shaped puncture though the bone.

According to the researchers, the fact that alterations to the bone's surface indicate healing means that the injuries were not fatal and the animal lived for some time after they were inflicted.

The poor dinosaur's life took a turn for the worse later, though. The preservation of the skull and other bones, as well as damage to the jaw bones show that the dinosaur died young and began to decay.

Shortly thereafter, a large tyrannosaur — probably from the same species — chomped into the dead teen dinosaur and presumably ate at least part of it.

The remains are unique in that they provide evidence for both combat between dinosaurs of the same species and cannibalism.

T. rex was closely related to Daspletosaurus. They essentially were cousins and grew to nearly the same sizes as adults. It's therefore likely that T. rex and other large carnivorous tyrannosaurs engaged in similar behaviour.

This article originally appeared on DiscoveryNews.com


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