There are many ways a tyrannosaurus rex could kill: it could bite you with its gigantic teeth, crush you with its heavy legs or slam you with its powerful tail. But it all becomes slightly less intimidating when you take a look at the size of its arms compared to its body. For years now, scientist have been trying to figure out why this was the case, and what the actual purpose of such tiny arms was. To give some clarity on this issue, our natural history experts are sharing some of the most recent theories about why the Tyrannosaurus Rex had such tiny arms and their possible purpose here.
Can’t have it all
Researcher Michael Habib has inspected this issue very thoroughly. He says that because the T. rex was one of the biggest meat eaters, it needed a very strong bite which required powerful jaw muscles and a large neck and head. But neck and arm muscles compete for muscle attachment space across the bones of the shoulder, so you can’t have both strong arms and a strong jaw. So if this is true, the arms might not have been very useful, but they did play a key role in the T. rex’s strength.
One theory states that because neck and arm muscles compete for muscle attachment space across the bones of the shoulder, the T. rex had small arms to allow for a strong jaw
So what was the purpose of the arms?
Some researchers theorise that the arms might have been vestigial - they used to have a purpose, but don’t anymore due to evolution - much like a human's tailbone or wisdom teeth. However this wouldn’t be the first time scientists or palaeontologists named something vestigial, simply because they haven’t yet found its true purpose.
Another theory concludes that males used their arms to grab onto females during mating, although this wouldn’t explain what the females used their arms for. Others speculate that the T. rex might have used its arms to lift itself up from the ground when laying, or having fallen down.
- Theories about the the T. rex's arms range from them being vestigial to having a role in mating
- Image source: National Geographic
Still others think the Tyrannosaurus Rex used its arms to hold onto its prey and Steven Stanley, a palaeontologist at the University of Hawaii in Manoa, believes the T. rex’s arms were "well-adapted to vicious slashing", but this is a controversial opinion, as many scientists think its reach is simply too small.
We hope this gives you some insight in why the Tyrannosaurus Rex has such tiny arms and what their possible purpose may have been. If you’re interested archeology & natural history, be sure to check out our weekly auctions to peak into the past and take home a souvenir.
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