Tyrannosaurs' skull shows scars of combat and bite marks from feeding


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They already have a fearsome reputation as the top predator of their time, but it seems the Tyrannosaurs were also prone to eating each other.

A new study has uncovered evidence that a relative of Tyrannosaurus rex, called Daspletosaurus, may have indulged in cannibalism.

Paleontologists have found bite marks on the fossilised skull of a juvenile Daspletosaurus, which lived around 75 million years ago.

This artist's reconstruction shows a Daspletosaurus feeding on the body of another in an act of cannibalism

This artist's reconstruction shows a Daspletosaurus feeding on the body of another in an act of cannibalism

While some of the injuries appear to have been sustained during combat with other tyrannosaurs, others appear to have occurred after death.

The scientists believe that another Daspletosaurus, which could grow to nine metres (30ft) as adults and weigh up to four tons, fed on the youngster's body.

DID T-REX HUNT IN PACKS?

Tyrannosaurus rex and its relatives were more intelligent than previously thought and hunted in gangs which included young and older members, researchers have claimed.

Scientists believe they have evidence that the top predatory dinosaurs were highly intelligent pack animals, despite T-rex being popularly depicted as a dangerous but dim-witted loner.

This is a myth that has grown up because for many years their fossil skeletons tended to be found on their own, researchers say.

The new theory follows an analysis of skeletons of the tyrannosaur Tarbosaurus bataar from 90 sites in the Gobi Desert, Mongolia.

Tarbosaurus, a cousin of T-rex that lived around 70 million years ago, was a two-legged predator up to 12 metres long and weighing five tonnes.

At least half a dozen of the animals appear to have belonged to a single social group, including adults and juveniles, that died together.

The findings help to shed light on the brutal world in which the dinosaurs inhabited.

Dr David Hone, a paleontologist at Queen Mary University of London, who led the research said: 'This animal clearly had a tough life, suffering numerous injuries across the head including some that must have been quite nasty.

'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.'

The researchers, whose work is published in the journal PeerJ, were examining the skull of a Daspletosaurus found in a quarry in the Dinosaur Provincial Park close to Calgary, Alberta in Canada in 1994.

Daspletosaurus, which means 'frightful lizard', is thought to be a close relative of the more famous Tyrannosaurus rex and roamed north America between 77 million and 74 million years ago.

With a massive, heavy skull that could be more than 3ft (1 metre) in length, it would have had a powerful bite and probably preyed on large armoured ceratopsid dinosaurs.

The dinosaur latest study was thought to be a juvenile, measuring just under 19.7 feet (6 metres) and weighed around half a tonne.

The researchers found numerous injuries on the skull, several of which appeared to match the teeth of tyrannosaurs.

The skull of the juvenile Daspletosaurus (above) was covered in bite marks made by Tyrannosaur teeth

The skull of the juvenile Daspletosaurus (above) was covered in bite marks made by Tyrannosaur teeth

David Hone (left) and Darren Tanke (right) studied the fossilised skull at the Royal Tyrrell Museum

David Hone (left) and Darren Tanke (right) studied the fossilised skull at the Royal Tyrrell Museum

One bite to the back of the head broke off part of the skull and left a circular tooth-shaped puncture through the bone.

However, there are signs the bone had begun healing, suggesting the injury was not fatal and that the animal lived for some time after it was inflicted.

While the researchers cannot say what killed the Daspletosaurus, damage on the jaw bones suggest that a large tyrannosaur bit into the dead creature between one and three times in what appears to be feeding behaviour.

Daspletosaurus is thought to have not just hunted but also scavenged for food and the research team say the injuries appear to have occurred after it had begun to decay.

Cannibalism is relatively common in the natural world, with more than 1,000 species known to eat their own species.

Daspletosaurus, shown in the artists reconstruction above,  led a violent life the study suggests

Daspletosaurus, shown in the artists reconstruction above, led a violent life the study suggests

Tyrannosaurus rex is also thought to have indulged in cannibalism, according to a study in 2010.

Writing in the journal, Dr Hone and his colleague Darren Tanke from the Royal Tyrrell Museum in Drumheller, Alberta, said the Daspletosaurus appeared to have lived a violent life involving battles with other members of its own species.

They said: 'Numerous wounds were inflicted during life and despite some considerable damage the animal clearly survived as shown by the evidence of healing.

'These were likely inflicted at least in part by one or more conspecifics and perhaps as a result of numerous separate instances of conflict.

'After death, the animal suffered at least one major bite to the right dentary, and perhaps two more from another tyrannosaurid, possibly another Daspletosaurus.

'The specimen must have been decaying prior to the delivery of the bite to the dentary, and the condition of other material suggests scavenging, rather than simply late-stage carcass consumption.'

 



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