why t. Did Rex have such short arms?
Tyrannosaurus rex It was a vicious predator with the strongest bite of any animal to walk the land. The beast roams late Cretaceous Desert 66 million years ago, looking for a Triceratops or eDmontosaurus cut to pieces
The only thing that isn’t scary about the tyrannical lizard king is its tiny weapon. T. Rex was not the only one Dinosaurs with short arms compared to the rest of the body; Many of its theropod cousins – a group of bipedal, mostly meat-eating dinosaurs – shared this trait. But why did many theropods evolve such unstable arms?
Scientists have proposed several possible explanations.
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A 2021 study published in the journal Polish Paleontological Journal (opens in new tab) As suggested by bone-crushing theropods T. Rex Evolved short arms to prevent them from biting each other’s arms while feeding. Paleontological evidence suggests that these animals devoured their prey as a pack (opens in new tab)So perhaps they evolved short limbs to avoid accidental arm ruptures when a group of theropods descended on a tackle. TriceratopsResearch authors suggest.
Right now, however, this is just a guess. “It’s a beautiful story,” said John Hutchinson, a biologist at the Royal Veterinary College in London who was not involved in the research. “But I think, ultimately, we really don’t know.”
Hutchinson, who studies the biomechanics of locomotion in large terrestrial animals—both living and extinct—looked at dinosaur forelimbs. evolution A different way: In the evolution of theropods, “the arms didn’t really get shorter, but the legs got longer,” he said.
“As animals get older, the snout gets smaller and the head gets bigger,” he continued. Tyrannosaurs, in particular, “adapted this bone-crushing killer bite to their heads, so they really specialized their heads, and then they really, really shortened their snouts.”
As tyrannosaurs and their theropod cousins developed larger heads and a bipedal posture, they used their forelimbs less. They start using their heads to catch and kill prey. As a result, according to this theory, their forelimbs did not grow as well as the rest of their bodies.
“An animal can devote so much of its body volume to one thing or another,” Hutchinson said. “He can’t be a jack-of-all-trades. So you either have a very generalized body where everything is equally specialized for some common ecological niche, or you’re really specialized. T. RexWho is super specialized to be a front-end hunter.”
T. Rex’s Weapons were too small to help it hunt and kill. These giant dinosaurs used a “puncture-pull” method to bring down prey, including T. Rex “They’ll bite big chunks out of them, tearing them backwards with their powerful necks,” Hutchinson said. Thus the modern Komodo dragon (Varanus comodoensis) hunting as well, he added. And their large hind legs help stabilize them. There is no evidence – at present – that their small arms helped in any way.
It is tempting to assume that every trait in an animal has some sort of evolutionary role to help the animal survive. But sometimes traits appear (or disappear) that don’t necessarily confer a clear-cut evolutionary advantage. In this case, that feature — nozzle length — didn’t change, other features did. other T. Rex Body parts have grown in size to help them survive in their ecological niche. Maybe Bahubali was not needed to grow with the rest T. Rex’s Body, they look relatively small.
But that may not be the whole story, Hutchinson said; T. Rex And other theropods may have used their arms for something, and it will take a lot more research and well-preserved fossils to find out.
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