Evolution shrunk T-rex dinosaur hands so they wouldn’t bite each other’s hands
The tiny arms of Tyrannosaurus rex (T-rex) are a topic of endless laughter for the online community. They made all kinds of pictures and situations, come up with enough jokes to make fun of that disproportionate arm.
After all, today we are too safe from the computer screen and no longer have to fear the extinct animals eating us. But why does the T-rex have tiny arms? After the cheers of laughter, many scientists were extremely concerned with this question.
They feel uncomfortable with that. There is no reason why a giant animal, up to 4 meters tall, 12 meters long and weighing nearly 7 tons has arms smaller than us. The hand of the T-rex dinosaur is clearly something that provokes OCD syndrome, which makes scientists obsessively confused and have to find an explanation for it.
After decades of research, many theories have been put forward. Some scientists say that the dinosaur T-rex is really not as useless as we think. It can become a powerful slashing weapon and Can lift objects weighing up to 200 kg.
The T-rex can also use its arms to grip its prey in front of its chest, then deliver a decisive bite with its huge and sharp teeth. One bold theory even suggests that the T-rex dinosaurs even held hands during sex.
But if the T-rex’s arm is useful, evolution would have to make it bigger and bigger, why shrink? A team of scientists at the University of California, Berkeley now thinks that: T-rex should also have big hands, but when they have too big hands, they are often accidentally bitten by their own kind. So it’s best that the T-rex has evolved to have smaller arms.
The mouth is big, the teeth are sharp, but the brain is small and clumsy
Accidents happen often in the world of reptiles. They mainly live by instinct, with small brains, little thought but possessing clumsy, dangerous teeth.
Watch the video clip below to see how easily an alligator can bite off another alligator’s hand:
Fighting for food, crocodiles bite off their fellow’s legs!
In the video above, you can see the oversized teeth that limit the crocodile’s vision. It could not see the bait and mistakenly bit the hand of the crocodile next to it. This crocodile even swallowed the stomach of his friend’s arm, without knowing it had bitten by mistake.
Tyrannosaurs are like crocodiles. It is a reptile and also lives by instinct. “What if a group of adult tyrannosaurs swarmed the carcass of a dead animal? You will have a series of giant skulls, with extremely powerful jaws and teeth that can tear and shred flesh and blood right next to you“, said biologist Kevin Padian from the University of California, Berkeley.
Let’s say the T-rex all have long arms, and one wants to tear food with their hands while the other wants to bite with their mouths. Then a very likely case, this T-rex will mistakenly bite another T-rex’s hand.
Another scenario Padian posed is that when the tyrannosaurs weren’t close to each other, they could turn to each other and the big arm would always be the first thing a T-rex would aim for in a fight. brawl.
Imagine a stranger leans over to put your arm around your shoulder, and you immediately slap their arm away. But with the T-rex, it will swat that arm with its mouth.
“What if one T-rex senses another T-rex is getting too close to it unnecessarily? It can warn the other by cutting off its arm.” Padi said.
“So maybe it’s a benefit to have atrophied arms. After all, tyrannosaurs don’t need to use their hands to hunt.”
Competing with other theories
Today, paleontologists understand more and more about dinosaurs thanks to the new fossils they discovered, not only bones but also dinosaur skin and feathers.
Along with the footprints in the mud stored over millions of years when the mud petrified, paleontologists were also able to reconstruct a wealth of information from gait, speed to the hunting behavior of dinosaurs.
But the complex questions of dinosaur evolution still baffle scientists, despite the fact that they already have DNA technologies to analyze their ancestral genomes. The T-rex arm is one such theme.
No other animal other than dinosaurs has developed such ridiculously small arms. Can you imagine what it would be like if a man was 1.70m tall but only had 10cm long arms?
Padian, in an effort to find an answer to that mystery, made a series of measurements on MOR 555, a complete T-rex dinosaur fossil stored at the Smithsonian Museum in Washington.
Using these measurements, he disproved previous theories – including both the sex assist arm and the slashed weapon. Padian thinks the T-rex’s arm is too small and weak to use.
Instead, he thinks having tiny arms could be an evolutionary benefit, to help them avoid accidentally biting each other’s hands while foraging.
“The longer arms, especially in the natural direction, had a forward extension that would have inserted themselves into the jaws of other dinosaurs, the deadliest jaws ever recorded on land.“, Padian said.
“If the dinosaurs bit each other’s hands, the danger of wounds, from amputation, infection, disease can eventually lead them to death. So it’s clear that evolution with small arms is a selective natural selection.”
“Therefore, we shouldn’t try to find functions and attribute them to these shrunken arms, but see if the reduction serves a larger purpose and how. “.
Of course, like the other suggestions above, Padian’s hypothesis is still just a hypothesis. Now, he will need evidence to prove his hypothesis is correct.
Padian thought he could find dinosaur skeletons with larger hands that had more bites on them. Or maybe he could analyze the bite marks on the bones of the tyrannosaurs to find that they bitten each other’s hands less after the hands had shrunk.
If these fossils can be collected and synthesized, it will prove to be true that the theory that tyrannosaurs often bit each other’s hands while eating is true. Then evolution makes their hands smaller as well.
at Blogtuan.info – Source: genk.vn – Read the original article here