The tiny arms of T. rex may have been useful after all MNN

Tyrannosaurus rex was considered one of the most formidable carnivores of its time. While the debate rages about whether it is a pure predator or a scavenger, we can all agree that T. rex seems to know he knew how to eat a meal.

A pair of tiny double-digit claws, however, detracted from its fierce appearance. They seemed to belong to a much smaller creature, not the so-called king of tyrant lizards.

However, scientists say that these lousy weapons could still be useful, if an analysis of the forerunners' close relatives is an indication.

Watch the present to understand the past

Christopher Langel, a bachelor of geology student, and Matthew Bonnan, a professor of biology at Stockton University, New Jersey, examined past members of a T. rex and examined members of the domestic turkey (Meleagris gallopavo). ) and the American Alligator (Alligator mississippiensis). They took the bones of the ulna and humerus from both animals and placed them in two devices creating an X-ray reconstruction of the moving morphology, or XROMM.

The XROMM allows researchers to create a 3D model of the bones of everything that is digitized. The motion data is then added to the scan and the result is a moving 3D image that, according to the XROMM website, allows scientists to see "a rapid bone movement, such as during the flight of a bird, the frog jump and the human race ".

Although XROMM can be used with live specimens, Langel and Bonnan only used turkey and alligator members for their study. The wings and arms were placed on a plexiglass platform between the XROMM machines. The two researchers then used a fishing line to pull on the elbow of each limb while the XROMM recorded the movements of the bones.

The American alligator could help scientists understand how T. rex moved his arms. (Photo: Wing-Chi Poon / Wikimedia Commons)

The results showed that the movements of the elbows of the two animals are complicated, much more than ours. "When we bend our elbows, the two bones of the forearm follow the articulation of the hinge to fold back up the arm," said the researchers on October 17 during the 78th edition of the Society of Vertebrate Paleontology. "Our hands often turn the palm of the hand upward when we bend our elbows, because a forearm bone pivots around the other.

"The elbow joint [for turkeys and alligators] is more complex, and the two bones of the forearm pivot not only around the joint, but [also] The researchers continued: "Unlike our elbows, the two bones of the forearm pull the palm of the hand to turn inward and slightly upward."

This, according to Live Science, surprised the researchers.

"It was particularly surprising how much the forearm bones could tilt from one elbow to the other, a movement that is essentially forbidden to mammals like us," said Langel. and Bonnan. "Essentially, alligators and turkeys can turn the palm of the hand inward and upward as we do, but [they do it] using more complex movements of the bones of the elbow. Once again, Mother Nature solved the same problem in different ways. "

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T. rex may have kept the arms turned inward. (Photo: JopsStock / Shutterstock)

Regarding what it means for T. rex, Live Science explains that it indicates that the dinosaur was a "clapper, not a slapper". This means that the T. rex would keep hands clasped inward, as if they were clapping, instead of facing downward and outward, as if they were slapping.

The results suggest that the T. rex arms may have been able to rotate the palm of the hand inward and upward so that the palm of the hand is facing the chest when the elbow was bent, "said the researchers.

Why would T. rex do this, however, remain a mystery since we can not really see the dinosaur in action.

"But we could assume that such a movement (rotation of the forearm and hand towards the chest) could allow some theropods to approach their prey for a mouthful," Langel said. Bonnan to Live Science in an email.

The duo's research has not been published in a peer-reviewed journal.

The tiny arms of T. rex may have been useful

According to studies conducted on turkeys and alligators, researchers suspect T. rex to turn his palms inward and upward – which could affect the way he eats and on this that he eats.