Robust bones and bearlike claws suggest the dino’s ridiculously small limbs were far from useless
SEATTLE — Tyrannosaurus rex may have had small arms, but it was no pushover.
This fierce dinosaur is known for its giant head, powerful jaws and overall fearsome appearance — except for those comical-looking arms. But the roughly meter-long limbs weren’t just vestigial reminders of a longer-armed past, paleontologist Steven Stanley of the University of Hawaii at Manoa said October 23 at the Geological Society of America’s annual meeting. Instead, the limbs were well-adapted for vicious slashing at close quarters, he argued.
T. rex ancestors had longer arms that the dinos used for grasping. But at some point, T. rex and other tyrannosaurs began to use their giant jaws for grasping instead, and the limbs eventually atrophied. Many people have hypothesized that the shrunken arms were, at best, used for mating or perhaps pushing