Trending Now - Study Reveals T. Rex's Tiny Arms Linked to Powerful Jaws

WHO:

ScienceAlert - Charlie Roger Scherer, vertebrate paleontologist at University College London, led the research.

Space Daily - The research team included Elizabeth Steell at Cambridge and Paul Upchurch at UCL.

WHAT:

ScienceAlert - A study suggests that T. rex's tiny arms evolved due to the development of powerful jaws, not because of body size increase.

Space Daily - The study analyzed data from 82 species of theropods, finding a strong correlation between reduced forelimb size and robust skulls.

Space Daily - T. rex scored highest in skull robustness among the 82 species analyzed, with Tyrannotitan coming in second.

WHERE:

Space Daily - The research was conducted at University College London and Cambridge.

WHEN:

Space Daily - The study was published on May 19, 2026, in the journal Proceedings of the Royal Society B: Biological Sciences.

WHY:

ScienceAlert - The arms shrank because they became unnecessary as the jaws evolved to become the primary weapon for hunting larger prey.

Space Daily - The study suggests that as prey, particularly sauropods, grew larger, theropods adapted by relying more on their jaws for hunting.

HOW:

ScienceAlert - Researchers quantified the reduction in forelimbs and developed a new system for scoring skull robustness based on size, estimated bite force, and relative dimensions.

Space Daily - The study involved a comparative analysis of forelimb length, skull robustness, and body size across the theropod group.

(UPDATED May 22, 2026 06:23 UTC)

A new study led by vertebrate paleontologist Charlie Roger Scherer from University College London reveals that the tiny arms of T. rex evolved not due to body size increase but because powerful jaws became the primary weapon for hunting larger prey. The research, which included contributions from Elizabeth Steell at Cambridge and Paul Upchurch at UCL, analyzed data from 82 species of theropods and found a strong correlation between reduced forelimb size and robust skulls, with T. rex scoring the highest in skull robustness. Published on May 19, 2026, in the journal Proceedings of the Royal Society B: Biological Sciences, the study suggests that as prey like sauropods grew larger, theropods adapted by relying more on their jaws for hunting.