T. rex was a Cannibal

Galvasean

"The tooth marks are typical of tyrannosaur tooth marks, and are just too big to come from any other carnivorous dinosaur," he said, adding that T. rex teeth were about 8 inches long.

Further supporting the attribution is the fact that T. rex is known to have been the only big carnivore in western North America 65 million years ago.

When Longrich searched through additional T. rex fossil collections from several different museums, he found other evidence that this dinosaur was a cannibal. Three foot bone fossils, including two toes, and one arm fossil all retained big tooth marks due to feeding.

While it's possible that all or some of the gouges were the result of scavenging, Longrich and his colleagues think it's likely that the dino-on-dino feasting happened after fights, a meal that would help the cannibal victor.

"You're killing a competitor and getting a free meal at the same time," he explained. "The hunting is going to be better if you eat the other hunters."

Battles between these mega carnivores must have been quite a spectacle.

"If I was a tyrannosaur facing another tyrannosaur face-to-face, I'd say the only real strategy is to wait for an opening and then go straight for the head," he said. "You'd want to clamp down on your opponent's neck or jaws to prevent it from fighting back. If you attack any other part of the body, then you're left open to counterattack."

Full article here.


Illustration by Mike Skrepnik

Not the first example of tyrannosaurs biting each other. More examples here and here.

Galvasean

Photo of bone (with toothmarks) from National Geographic.