Why are T. Rex arms so small? A researcher advances a new hypothesis.

DINOSAURS – This is one of the great mysteries surrounding the best-known dinosaur. Why are Tyrannosaurus Rex’s arms so ridiculously short? This question has regularly come back to paleontologist Kevin Padian, a professor at UC Berkeley, who offers a new hypothesis.

In fact, although several theories have been formulated, none has achieved consensus. the paleontologist then he looked at the matter from another angle. Instead of wondering what their weapons were for, why not find out what strategic advantage those small arms had for the survival of the species?

Thus, the paleontologist raises a new hypothesis in an article published in a scientific paleontology journal (Polish Paleontology Act): the length of the arms of T. rex decreased to avoid accidental or intentional amputation by their congeners.

Small arms to avoid danger.

To do this, it is inspired by a recent discovery about the group of tyrannosaurids. In fact, paleontologists postulate that some hunted in packs, having discovered in recent years many sites that brought together several specimens adult and juvenile tyrannosaurs.

“What if multiple adult tyrannosaurs converge on a carcass? You have a group of massive skulls, with incredibly powerful jaws and teeth, tearing and gnawing through flesh and bone right next to you. What if your friend thinks you’re getting too close? It could warn you by cutting off your arm,” explains the paleontologist.

If the amputation is extreme, any cut or wound could cause infection, bleeding, and possibly death. The Berkeley professor therefore states that “it might be an advantage to reduce the forelimbs, since you’re not using them in predation anyway.”

analogy with crocodiles

Kevin Padian’s hypothesis finds analogies in some animals awesome today. This is the case of the Komodo dragon (Varanus komodoensis), a giant lizard that lives on Komodo Island in Indonesia. Hunting in groups, everyone rushes to the party when prey is killed. The larger dragons obviously have priority and leave the rest to the smaller ones. In all this activity mutilations can occur.

This is also the case for crocodiles during feeding. At mealtime, frenzy seizes the group and a bite serves as a warning to demonstrate their superiority. It is also possible for one of them to miss the target during a bite. This video from an Australian zoo bears witness to this kind of behavior.

To confirm his hypothesis, the paleontologist proposes checking the presence of bite marks on specimens from museums around the world. But “it would be a real fossil collecting feat,” he admits.

many other theories

The hypotheses that try to discover the usefulness of the weapons of the T. rex are numerous and do not date from yesterday. Since the discovery of the first fossils in 1900 by the dinosaur hunter Barnum Brown, the size of its forelimbs intrigued. Brown even wonders if the arms aren’t too small to be part of the skeleton.

His colleague, Henry Fairfield Osborn, who described and named the tyrannosaurus rex, then proposed a hypothesis: these tiny appendages would serve as “pectoral claws”. Its usefulness would then be to keep the female in her place during copulation. The problem is that Henry Fairfield Osborn provides no evidence, although it is clear that the bras of T. rex are too short to encircle a congener.

Other explanations have subsequently been proposed to explain the size of the arms: waving them to attract a mate or send social signals, serving as an anchor to allow the animal to get up, holding onto prey, stabbing an enemy, and even prodding an animal. sleeping triceratops evening. However, today there is no consensus on any theory.

“Thinking about social organization”

In fact, as Professor Kevin Padian explains, “the arms are too short.” “They can’t touch each other, they can’t reach their mouths, and their mobility is so limited that they can’t stretch very far, either forward or up.” Some paleontologists will then postulate that the arms had no function and it is not useful to worry about that.

However, this hypothesis does not seem viable, since the ancestors of the tyrannosaurids had longer arms. So there must be a reason why evolution reduced them in both size and joint mobility. This is all the more true since this evolution is common to several groups of theropods (a group of carnivorous dinosaurs), such as the abelisaurids or the carcharodontosaurids.

Presenting a new approach to the question, Kévin Padian’s theory is plausible. But the professor does not seek at all costs to validate it. The essential is elsewhere, according to him. “The first thing he wanted to do was establish that conventional functional ideas just don’t work,” he said.

Therefore, the professor wants to pick up the problem from the beginning, to examine it from a new angle: “We can take an integrative approach, thinking about social organization, feeding behavior and ecological factors beyond purely mechanical considerations.”

See also in The HuffPost: This Flying Reptile Is The Largest Ever Discovered In The Jurassic

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