If T. Rex ’s Beady-Eyed Glare Terrifies You, It Should

It was an unlucky dinosaur that came face to face with the rex. The seven-metric-ton predator, which hunted through the end of the Cretaceous period 65 million years ago, was not the only beast with these features. The squinty eyes may be a trade-off for powerful jaws.

Stephan Lautenschlager, a paleobiologist at the University of Birmingham in England, discovered this connection while studying the skulls of hundreds of extinct archosaurs. It's possible to see a lot about an animal. The eye sockets of fossils give scientists a good idea of eye sizes. The T. rex had a skull that accommodated its large eyes. If a T. rex had 20 percent of its skull taken up by its eyes, it would have a huge eyeball 30 centimeters in diameter and 20 kilograms heavy. It would have to eat more just to maintain its huge eyeballs if it had large eyes. It might increase the vision acuity, but it's probably not efficient.