Why did T. rex have such tiny arms? Scientists now think it’s because its giant head became the ultimate hunting tool. Across ...

T. rex and other giant dinosaurs evolved tiny arms because their skulls and bites became powerful enough to replace forelimbs ...

A new hypothesis for the evolution of the T. rex’s short arms was formulated by Kevin Padian, UC Berkeley professor emeritus of integrative biology and curator of paleontology at the UC Museum of ...

A new analysis of fossils believed to be juveniles of T. rex now shows they were adults of a small tyrannosaur, with narrower jaws, longer legs, and bigger arms than T. rex. The species, Nanotyrannus ...