Why does the T-rex have nice arms?
Various predatory dinosaurs, or the so-called T-rex, had small arms that were not proportional to their body.
How is that?
For information, the average length of a T-rex is about 13 meters, the length of the skull reaches 1.5 meters, but the length of the arms is less than 1 meter, and the weight can reach 8 tons.
In a new research paper appearing in the latest issue of Acta Palaeontologia Polonica on the T-rex arm size hypothesis, small arms are an adaptation to hunting patterns.
Kevin Badian, professor emeritus of integrative biology at UCLA, said paleontologists have found evidence that some tyrannosaurs hunted in groups, not alone, as shown in many of the paintings and dioramas.
“Several important mining sites that have been excavated in the past 20 years preserve both adult and young tyrannosaurs,” the official website quoted him as saying. .
It is also suspected that the T-rex’s small arms are intended to prevent physical contact when swarming around prey, according to reports.
This is to prevent clashes with similar species when crowding carcasses of food or eating them with great force.
“What if several adult dinosaurs gathered around the corpse? You have a lot of huge skulls, with very strong jaws and teeth, tearing and chewing flesh and bones next to you,” Badian said.
“What if your friends over there think you’re getting too close? He might warn you to cut off your arm.”
As discussed earlier, T-rex is an assembler type. Thus, small arms are intended to avoid disturbing the juvenile T-rex when crowding prey in adult groups.
Badian noted that the ancestors of Tyrannosaurus had longer arms. According to him, there must be a reason for the contraction of the organ in terms of size and mobility of the joints.
However, he did not deny that any hypothesis regarding the short arm of the T-rex, including its counterpart, would be difficult to prove because the species became extinct 66 million years ago.
hug the opposite sex
Barnum Brown, a large dinosaur fossil hunter, once had doubts when he discovered the first T-rex fossil found in 1900. The reason is that this T-rex has a very small arm compared to its body frame.
His colleague, Henry Fairfield Osborne, who described T. rex and named it T. rex, hypothesized that the short arms were probably limbs that held the female in place during copulation (pectoral claspers).
However, Osborne did not provide evidence. Badian noticed that the arms of a T-rex were too short to hold another T-rex, and certainly too weak to control his partner.
Several decades after the discovery, many researchers were looking for why the predator had hands only a distance of at least 1 meter.
Some experts believe that the short arms serve to attract mates or social cues, and act as anchors to help the species rise from the ground, grab prey, stab enemies, and even propel Triceratops species at night.
Quoting Badian also postulated that natural selection favored shorter front legs, because the arms were of little use to carnivores.
Some paleontologists have even suggested that this T-rex’s arm had no function at all.