Adult tyrannosaurs were basically two-legged bone-crushing machines. New research suggests that juvenile tyrannosaurs could not match the same level of brutality, resulting in a distinct bite that sets them apart from their adult counterparts.
Nothing like tyrannosaurs exists today, and thank God for that. As the quintessential top predator of the Mesozoic, these megateropods showed biting forces that confuse the imagination. The modern lion exerts a respectable 1,300 Newtons of force when the prey descends, but T. rex– with his jaw wide and deep fixed – he exerted a quantity of 60,000 Newtons of force with each awful bite.
“Adult T. rex it is estimated to have possessed some of the greatest impact bite forces recorded in any animal, with enough power to crush a machine based on previous studies, ”wrote Andre Rowe, a doctoral student in geology at the University of Bristol, in a e-mail. “While the massive size of the animal and the huge muscles were essential in the administration of its amazing bite, there is also significance in its shape, as I discovered that the thin jaw of the younger forms was less able to withstand the stress of such a bite. big.”
This is the main finding of a new study led by Rowe, published on Tuesday in the scientific journal Anatomical Record. The new paper provides further evidence that juvenile tyrannosaurs were strikingly different from their adult versions and that they occupied – and probably dominated – a separate ecological niche.
The aim of the new study was to explore how the feeding techniques of the large predatory dinosaur changed during the various stages of growth. Previous research has shown that the minor T. rex it had a thin jaw, which eventually became the deeply iconic jaw seen in adults. Rowe and colleagues “wanted to test the functional significance of this change,” he said.
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To do this, the researchers ran 3D biomechanical models based on CT scans taken completely T. rex skeletons, and inferences about muscle size, shape, and placement. For a minor T. rex model, the researchers tested a young Mongolian tyrannosaurus named Raptorex kriegsteini.
“The main method we used in our study was an engineering technique called finite element analysis, which reveals stress and tension in solid structures,” Rowe explained. “Areas of tested structures with a high risk of rupture will display” hot “He likes red and white, while there “cold”Rs, such as green and blue, indicate the points where the risks of breakage are minimal.
Tests of juvenile and adult tyrannosaurs at equal lengths of the jaw showed that young people endured greater stress, indicating the need for a wide and deep jaw shape in adults. The key to this discovery was an analysis of T. rex pterygoid muscles, which are located at the lower end of the back of their mandible.
“Since we were applying virtual muscles to these dinosaurs to get accurate results, we had the opportunity to test the significance of individual muscles during feeding,” Rowe said. “The pterygoid muscles have been found to lower the bending tensions near the front of the jaw, where T. rex you may have applied the bites with the greatest impact using massive, conical teeth. ”
As an interesting part, it exercises modern crocodiles their greatest forces of movement towards the back of the jaws, while in tyrannosaurs, is in front.
Rowe’s new paper suggests that the thin jaws of adolescent tyrannosaurs would have been susceptible to severe damage if the shape of the mandible had remained the same throughout adulthood. But this is not the case, as a wider adult T. rex the mandible is able to absorb the extraordinary forces needed to crush the bone. In terms of specifics, a minor T. rex with a thin jaw – but with the length of an adult jaw – it should have withstood 3.3 times the stress, which would not have worked. From here and dramatic physical differences observed in juvenile and adult tyrannosaurs.
“Adult tyrannosaurs are noted for their bite which they used to swallow whole pieces of meat and bone, but the young people were not prepared for such a bite and therefore could have used a cutting bite which they could eventually overcome. ” explained Rowe.
So instead of hunting massive herbivores like Triceratops and Edmontosaurus, juvenile T. rexes probably hunted smaller dinosaurs and possibly even small species of mammals that existed in the late Cretaceous, a period that ended about 66 million years ago.
“While the adult T. rex he remains an iconic top killer, it’s pretty remarkable to think he started out as a thin-bodied animal that followed the struggling mammals, ”said Rowe.
Kat Schroeder, a doctoral candidate at the University of Mexico, who was not involved in the new study, said new research supports an idea presented in her recent paper paper, that juvenile tyrannosaurs were physically different enough from their parents to act as their own “morphospecies” and could have competed with other medium-sized theropods.”
Schroeder said the relatively small sample used for the new study is “limiting,” but “science is well done,And “it fits with the hypothesis that tyrannosaurs drastically changed their hunting style as they grew up.”
Looking ahead, Rowe would like to see further work on dinosaurs and other extinct animals and how their feeding style changes over time.
“CT scanning and 3D modeling techniques have provided us with wonderful information on the biology of dinosaurs, and the methods are applicable to both living and extinct animals,” he said.