Animal of the week: Why did Tyrannosaurus rex have such unfortunate small forelimbs?

Give worry a horse when it has a bigger head, goes the old saying. But the head was even bigger With Tyrannosaurus rexwith the king of the monstrous lizards. The skull of the ancient great beast was the size of a refrigerator, up to one and a half meters long.

T. rex also used its head a lot. Not so much for thinking or worrying about things, but for killing. With its powerful jaws, T. rex was able to crush even bigger dinosaurs and tear its prey to pieces.

But why did it have such unlucky hands? T. rex’s forelimbs were notoriously short and stubby, with only two toes. If we humans had such short arms in proportion to our body size, it would be like having two steak forks sticking out of our armpits.

Maybe things are connected. The front limbs of the beast were so short precisely because it had such a big head. This is what British researchers present in a recent report of the Royal Society in a scientific publication.

Attempts have been made to come up with many uses for short paws. It has been thought, for example, that T. rex would have used them to hold prey in place or take support when mating. More likely, however, they have atrophied out of their futility, when in the evolution of the tyrannosaurus, natural selection has emphasized strengthening the structure of the head instead of the forelimbs.

For T. rex, the head was the main weapon.

Researchers mathematically correlated the skull structure and the size of the forelimbs of different dinosaurs and observed a clear connection: the more robustly structured the predator’s skull was, the weaker the forelimbs it had. When there is limited energy for the development of the body, nature has to make a choice.

“It’s not convenient to try to tear and tear apart a 30-meter prey animal with claws. Attacking and grabbing with strong jaws is more effective,” explains the study’s lead author, a paleontologist Charlie Scherer.

T. rex faced life head on. It was practically like a running shark.

Although T. rex’s soft paws have been admired, some carnivorous dinosaurs had even weaker equipment. Some abelisaurs had no forelimbs at all, only small snouts. For example Carnotaurus sastrei mostly resembled a stick with legs.