Scientists say they may have discovered why T. rex had such small arms: “Evolution doesn’t like to have everything all at once”

For decades, the small arms of Tyrannosaurus rex have been one of paleontology’s greatest mysteries. Why did one of the most fearsome predators in history have such tiny forelimbs? According to a new scientific study, researchers may have finally found the answer.

The study, published in Proceedings of the Royal Society B, examined 85 species of carnivorous dinosaurs and concluded that reduced arm size was a direct consequence of the evolution of increasingly larger and more powerful skulls.

According to the researchers, T. rex relied primarily on its skull and bite as hunting weapons. Maintaining long, powerful arms also required a significant amount of energy, so evolution ultimately favored the traits that provided the greatest survival advantage. “Evolution doesn’t like to have everything all at once,” explained Charlie Roger Scherer, the study’s lead author to CNN. In his view, once the dinosaur had developed a massive head capable of killing prey on its own, its arms became far less important.

Experts compare T. rex to a kind of giant land shark that did almost everything with its mouth. Its bite was so powerful that it did not need to rely heavily on its forelimbs to attack or restrain prey. The study also found that this trait was not unique to T. rex. Other large carnivorous dinosaurs evolved the same pattern: enormous heads paired with progressively smaller arms. This has led researchers to believe that it was a highly successful evolutionary strategy that persisted for millions of years.

T. Rex arms likely served a hidden purpose

To reach these conclusions, the research team compared fossils and measured both arm size and the strength and structure of skulls across different species. T. rex stood out in particular for possessing one of the strongest skulls among all the dinosaurs analyzed.

Even so, researchers do not believe the arms were completely useless. Although they still do not know exactly what purpose they served, they suspect the limbs had some secondary function, since evolution rarely preserves body parts that provide no benefit at all.

Most importantly, the study highlights the remarkable ways dinosaurs evolved to survive. It demonstrates how species could develop dramatically different adaptations, even if doing so resulted in one of the most unusual and recognizable body plans in prehistoric history.

Get closer to the game! Whether you like your soccer of the European variety or that on this side of the pond, our AS USA app has it all. Dive into live coverage, expert insights, breaking news, exclusive videos, and more. Plus, stay updated on NFL, NBA and all other big sports stories as well as the latest in current affairs and entertainment. Download now for all-access coverage, right at your fingertips – anytime, anywhere.

And there’s more: check out our TikTok and Instagram reels for bite-sized visual takes on all the biggest soccer news and insights.