Adult tyrannosaurs were basically bone-breaking machines on two feet. New research suggests that juvenile tyrannosaurs could not match at the same level of cruelty, leading to a characteristic bite that distinguishes them from their adult counterparts.
Nothing like tyrannosaurs exists today, and thank you for that. As the main peak of the Mesozoic, these megateropods had biting forces that thwarted the imagination. The modern lion exerts a respectable 1,300 tons of power when crashing on prey, but T. rex—With his wide and deep jaw – exerted a whopping 60,000 tons of power with each horrific bite.
‘Adult T. rex it is estimated that it possessed some of the greatest biting forces recorded in any animal, with enough power to crush a car based on previous studies, ‘said Andre Rowe, a PhD student in geology at the University of Bristol, written in an email. ‘While the animal’s enormous size and large muscles were the most important to deliver its astonishing bite, there is also meaning in the shape, as we found that the slender lower jaw of the younger shapes was less able to withstand the strain of such resist a high bite. “
This is the main finding of a new study led by Rowe, Published on Tuesday in the scientific journal Anatomical Record. The new article provides further evidence that juvenile tyrannosaurs are markedly different from their adult versions, and that they occupy a separate ecological niche – and probably dominate.
The point of the new study was to investigate how the feeding techniques of large predatory dinosaurs changed during their different growth stages. Previous research has shown that the youth T. rex has a slender jaw, which eventually grows into the iconic deep-set jaw seen in adults. Rowe and his colleagues “wanted to test the functional importance of this change,” he said.
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To do this, the researchers performed 3D biomechanical models based on CT scans completed T. rex skeletons, and inferences about muscle size, shape, and placement. For a youth T. rex model, the researchers tested a young tyrannosaurus from Mongolia named Raptorex War Stones.
“The most important method we used in our study was an engineering technique called finite element analysis, which reveals stress and strain in solid structures,” Rowe explained. ‘Areas of tested structures with a high risk of breakage will show’ hot ‘colors like red and white, while ‘cold’ colors such as green and blue indicate points where the risk of breakage is least. ”
Tests of the juvenile and adult tyrannosaurs at equal jaw lengths showed that the juveniles endured higher stress, indicating the need for a deep, broad jaw shape in adults. The key to this finding was an analysis of the T. rex pterygoid muscles, located at the base of their lower extremities.
“As we applied virtual muscle to these dinosaurs to get accurate bite results, we had the opportunity to test for the importance of individual muscles during feeding,” Rowe said. “It was found that the pterygoid muscles reduce the bending stress near the front of the jaw, where T. rex possibly inflicted its highest blow bite using its massive, conical teeth. ”
As an interesting aside, modern crocodiles work their highest biting forces backwards in their jaws, while in tyrannosaurs, it’s forward.
Rowe’s new article suggests that the slender jaws of adolescent tyrannosaurs would be susceptible to severe damage if the jaw shape remained the same during adulthood. But this is not the case, as the broader adult T. rex lower jaw can absorb the tremendous forces needed to crush bone. In terms of details, a youthful T. rex with a slender jaw – but with the length of an adult jaw – it would have to withstand 3.3 times the tension, which would not have worked. Hence the dramatic physical differences seen in juvenile and adult tyrannosaurs.
‘Adult tyrannosaurs are known for their broken bite, “which they used to swallow pieces of meat and bone whole, but the youths were not equipped for such a bite and could therefore have used a cut bite that would eventually outgrow,” Rowe explained.
Instead of hunting down massive herbivores like Triceratops and Edmontosaurus, youthful T. rexes probably hunted smaller dinosaurs, and possibly even the small mammal species that existed during the Late Cretaceous, a period that ended about 66 million years ago.
‘While the adult T. rex remains an iconic killer of the summit, it’s quite remarkable to think that it started as a slender animal chasing scurrying mammals, ”said Rowe.
Kat Schroeder, a PhD candidate at the University of Mexico who was not involved in the new study, said the new research supports an idea presented in her recent version paper, that ‘juvenile tyrannosaurs were physically different from their parents to act as their own’ morphospecies’, and that they might be able to compete with other medium-sized teropods.”
Schroeder said the relatively small sample size used for the new study was’ limiting ‘, but the’ science is well done,And it fits with the hypothesis that tyrannosaurs have drastically changed their hunting style as they grow. ”
Looking ahead, Rowe wants to see further work done by dinosaurs and other extinct animals, and how their feeding styles change over time.
“CT scanning and 3D modeling techniques have given us amazing insights into dinosaur biology, and the methods apply to living and extinct animals,” he said.