Scientists Finally Discover What T Rex Used Its Tiny Arms For


The Tyrannosaurus Rex’s disproportionately small arms actually worked to its advantage, scientists have revealed.

Scientists have long-suggested the dinosaur’s tiny arms might have been used to holds its prey, or to grip tight during mating season, writes National Geographic.

During a Geological Society of America meeting in Seattle, at the end of October, a team of scientists at University of Hawaii said the T Rex’s arms were not actually as tiny and insignificant as they are perceived to be – and were actually ‘a metre long in most cases’.

Universal Pictures

The scientists said they’ve discovered the arms and claws were ‘adapted for slashing enemy dinosaurs at close quarters’ – and the short length of the arms would work to the T Rex’s advantage.

They also found although they may have looked incredibly tiny and ‘laughable’, they were actually very strong and had extremely robust bones which could ‘withstand a frenzied slash attack quite comfortably’.

Dr Steven Stanley said:

Its short, strong forelimbs and large claws would have permitted T Rex, whether mounted on a victim’s back or grasping it with its jaws, to inflict four gashes a metre [three feet] or more long and several centimetres [more than an inch] deep within a few seconds.

And it could have repeated this multiple times in rapid succession.

The unusual reduction of the number of fingers from three to two would have resulted in 50% more pressure being applied to each claw.


Dr Stanley also asked:

Since related dinosaurs also slashed their prey, in light of its formidable weaponry, why should T Rex not have engaged in this activity?

To make his case, the Stanley pointed out the T Rex’s strong arm bones, which he said would have made ‘effective slashing tools’, while an ‘unusual quasi-ball-and-socket joint’ would have ‘allowed the arms to move in several directions, ideal for slashing’.

He also said tyrannosaurs ‘lost one of their three claws during the course of evolution’, resulting in ’50 per cent more pressure being able to be applied by each of the two remaining claws’ — making it all the better for an all-powerful slashing.

Universal Pictures

But not everybody was left convinced, other experts are yet to be persuaded by this new theory.

Jakob Vinther, a paleobiologist from the University of Bristol, was at the meeting.

He told National Geographic:

It seems illogical to me to use such small arms to slash with.

He said without ‘further evidence’, he favours the idea of the arms being used for a ‘minor subsidiary purpose’ such as to keep hold of a mate during sex. That said despite Dr Stanley’s claim suggesting the claws would have been ‘dangerous to use while mating’.

Universal Pictures

And Thomas Holtz, a tyrannosaur expert at the University of Maryland in College Park argued the three-foot long arms would give a full-grown T Rex an ‘awkwardly short reach for slashing’.

He added:

I would expect it could cause some decent damage if it struck, but in order to deploy [the arm], Tyrannosaurus would basically have to push its chest up against the side of the victim.

In such a position the tyrannosaur wouldn’t be able to use its far more powerful armament: its massively powerful jaws.

I’ll never be able to watch a Jurassic Park movie in the same way again.