More from the article ...

... The study suggests that as their prey grew bigger, tyrannosaurs and other large predatory dinosaurs evolved to use their powerful jaws as their primary weapon.

As such, their arms shrank over time with disuse, until they became the funny little chicken wings we laugh at today.

This research is far from the first to suggest that these puny limbs were vestigial, but it goes further by linking the shrinking arms with the evolution of huge, powerful heads and jaws.

@#2 ... Do we have evidence of T-rex with longer chicken wings? ...

Insightful question.

More from the article ...

... Then, the researchers compared the length of the forelimbs with the length and robustness of the skull in 61 theropod species.

Sure enough, the link between reduced forelimbs and skull robustness was found to be strong in five separate families of theropods: tyrannosaurids, abelisaurids, carcharodontosaurids, megalosaurids, and ceratosaurids.

Skull or body size alone didn't seem to correlate with forelimb size. Many of these predators grew into behemoths, but some stayed relatively small, even while packing a powerful head/tiny arm combo.

Stranger still, the team found that, across different lineages, the arms shrank by different proportions. In some cases, the whole limb shrank in tandem, but in others, some parts shortened more than others. ...

If you want to learn more ...