What survival advantage did Tyrannosaurus rex's short arms have?

Paleontologists have made a series of hypotheses about T.

Rather than asking what T.

In a paper published in a recent issue of the journal Polonica Paleontology, Padian proposed a new hypothesis: When a group of Tyrannosaurus rex, armed with massive heads and bone-crushing teeth, raided a Tyrannosaurus rex's arms contracted to prevent accidental or intentional amputations

"What if several adult tyrannosaurs gathered on a corpse? You have a bunch of huge skulls with incredibly powerful jaws and teeth, tearing and chewing the flesh and bone next to you

Severe bites can lead to infection, bleeding, shock and ultimately death, he said

There must be a reason why T.

Padian said: "All the ideas on this issue are either untested or simply impossible because they simply don't work

He admits that any hypothesis, including his own, would be hard to prove 66 million years after the last T.

Arm and Tyrannosaurus Rex

When the great dinosaur hunter Barnum Brown discovered the first T.

For more than a century, other explanations for the short arms include waving to attract a mate or signaling socially, acting as an anchor to get T.

Padien approached the question from another angle, asking how short arms are good for the survival of animals

He said: "Several important quarries have been unearthed over the past 20 years to preserve adult and juvenile T.

Perhaps, he thought, the arms were meant to stay out of the way in the group foraging

In his new paper, Padian examined other paleontologists' guesses, none of which seemed to be well-tested

"The arms are too short," he said

Twenty years ago, two paleontologists analyzed T.

Firm confirmation of this hypothesis may never be possible, but a correlation can be found if you examine bite marks from museum specimens around the world, Padian said
.
He conceded that this would be a big feat for fossil fuel crowdsourcing
.

"Bites on the skull and other parts of the skeleton are well known in tyrannosaurs and other carnivorous dinosaurs," he said
.
"If fewer bite marks are found on the amputated limb, that could be a sign that the amputation was effective
.
"

But Padien doesn't fantasize that his idea will be the end of the story
.

He said: "What I initially wanted to do was show that the prevailing idea of ​​functionality simply doesn't work
.
That brings us back to where we started
.
We can then take an integrated approach that considers social organization, feeding behavior and ecological factors, while Not purely mechanical considerations
.
"

One problem with establishing this hypothesis is that there have been several groups of large carnivorous dinosaurs that have reduced their forelimbs independently, albeit in different ways
.

"The size and proportions of the limb bones were different in these groups, but so were other aspects of their skeleton," Padian said
.
"We shouldn't expect them to decrease in the same way
.
The same goes for the large, flightless mousebirds like ostriches, emus and rheas
.
They've clearly gone down different evolutionary paths for their own reasons
.
"

Partian sees a common thread in explaining the history of T.
rex's short arms and other features
.

He said: "For me, this study of the role of the arm is interesting because of the way we tell stories in science and what can be used as an explanation
.
We tell a lot of these stories about the possible function of T.
rex.
, because it's an interesting question
.
But are we really looking at it in the right way?"

KEVIN PADIAN.
Why tyrannosaur forelimbs were so short: an integrative hypothesis .
Acta Palaeontologica Polonica , 2022; 67