Study links T. rex short arms to stronger predatory skulls

A new study suggests the famously short arms of Tyrannosaurus rex and other large predatory dinosaurs evolved as their massive, powerful skulls became their primary hunting tools. The research, published in the journal Proceedings of the Royal Society B, indicates this shift was driven by the need to subdue increasingly gigantic prey.

Scientists from University College London analyzed data from 82 species of theropods, a group of two-legged, mostly carnivorous dinosaurs. They found that reduced forelimbs evolved independently in at least five distinct lineages: tyrannosaurids, abelisaurids, carcharodontosaurids, megalosaurids, and ceratosaurids. The analysis revealed a stronger correlation between short arms and robust skulls than between arm length and overall body size.

Lead author Charlie Roger Scherer stated that the relationship points to a major change in hunting strategy. He explained that as prey like massive sauropods grew larger, predators likely relied less on grasping with claws and more on delivering devastating bites. The head essentially took over from the arms as the method of attack, Scherer said, describing it as a case of "use it or lose it" where unused limbs...