Study Says T. rex Evolved 37-Centimeter Arms to Avoid Feeding Injuries

3 articles · Updated · The Brighter Side of News · May 14

A new study by UC Berkeley paleontologist Kevin Padian argues T. rex’s tiny forelimbs may have been favored because shorter arms were less likely to be bitten off during crowded feeding on carcasses.
Measurements from a mounted T. rex skeleton found the humerus was about 37 centimeters long versus a 120-centimeter skull, leaving the hands unable to reach the mouth, each other, or prey in practical ways.
That anatomy undercuts long-running ideas that the arms held prey, helped the animal stand, clasped mates, or fought enemies, and shifts the question from what the limbs did to why they shrank.
Padian links the hypothesis to fossil sites preserving multiple tyrannosaurs together and to dangerous communal feeding seen in Komodo dragons and crocodilians, where severe bites can cause hemorrhage, infection, shock, and death.
The paper, published in Acta Palaeontologica Polonica, proposes testing the idea by surveying museum specimens for bite-mark patterns across forelimbs, skulls, ages, and related giant theropods.

Does the T. rex's arm problem reveal a common evolutionary rule for giant predators?

Did T. rex's arms shrink to avoid being ripped off during violent group meals?