You know what they say about a dino with small arms? They got big, strong heads.

Summary:

Why did T. rex have such tiny arms? Scientists now think it's because its giant head became the ultimate hunting tool. Across multiple di- nosaur groups, stronger skulls and crushing jaws evolved alongside shrinking forelimbs, especially in predators hunting enormous prey. In other words, once the bite became deadly enough, the arms may have stopped mattering.

left over from earlier crawling version. lizard