Overview
- A peer-reviewed study published in May 2026 analyzed morphological data from 82 theropod species and found a recurring correlation between shortened forelimbs and robust, reinforced skulls.
- The team developed a new skull-stability metric to compare skull strength across taxa and reported Tyrannosaurus rex as scoring highest on that measure.
- The correlation appears independently in multiple theropod lineages, with examples such as Carnotaurus and Majungasaurus showing similar combinations of small arms and powerful jaws.
- Authors propose a 'use it or lose it' dynamic and an evolutionary 'arms race' in which growing sauropod prey favored biting and skull strength over grasping forelimbs.
- The researchers emphasize the result is correlational not causal and call for more fossil evidence, biomechanical tests, and ecological data to confirm whether stronger jaws drove forelimb reduction.