rex and certainly too weak to exert any control over a mate. rex’s arms are too short to go around another T. But Osborn provided no evidence, and Padian noted that the T. This is analogous to some sharks and rays’ pelvic claspers, which are modified fins. rex, hypothesized that the short arms might have been “pectoral claspers” - limbs that hold the female in place during copulation. His colleague, Henry Fairfield Osborn, who described and named T. rex fossils in 1900, he thought the arms were too small to be part of the skeleton. When the great dinosaur hunter Barnum Brown discovered the first T. He admitted that any hypothesis, including his, will be hard to substantiate 66 million years after the last T. And in every case, all of the proposed functions would have been much more effective if the arms had not been reduced.” “And none of the hypotheses explain why the arms would get smaller - the best they could do is explain why they would maintain the small size. “All of the ideas that have been put forward about this are either untested or impossible because they can’t work,” Padian said.

rex, which lived in North America at the end of the Cretaceous period, he said, but the African and South American abelisaurids from the mid-Cretaceous and the carcharodontosaurids, which ranged across Europe and Asia in the Early and Mid-Cretaceous periods and were even bigger than T. Padian noted that the predecessors of tyrannosaurids had longer arms, so there must have been a reason that they became reduced in both size and joint mobility. Severe bite wounds can cause infection, hemorrhaging, shock and eventual death, he said. “So, it could be a benefit to reduce the forelimbs, since you’re not using them in predation anyway.” What if your friend there thinks you’re getting a little too close? They might warn you away by severing your arm,” said Padian, distinguished emeritus professor of integrative biology at the University of California, Berkeley, and a curator at the UC Museum of Paleontology (UCMP). “What if several adult tyrannosaurs converged on a carcass? You have a bunch of massive skulls, with incredibly powerful jaws and teeth, ripping and chomping down flesh and bone right next to you. rex in the atrium of UC Berkeley’s Valley Life Sciences Building shows how peculiarly short the forearms were, given that the creature was the most ferocious predator of its day.

Rex reason