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.