Serrated Teeth Helped T. Rex Rip Through Muscle And Bone, Turning Him Into Top Predator

The T. rex was undeniably the ancient world’s deadliest predator. And it turns out, the dinosaur had a hidden weapon that made him so fierce — teeth like a steak knife.

The T. rex’s serrated teeth actually helped preserve their bite longer, and more gruesomely, made it easier for them to rip through the muscle and bone of their dinner, BBC reported.

This serration isn’t exclusive to the T. rex, however, but all theropods, a group of bipedal carnivorous dinosaurs that also includes the Velociraptor. This hidden structure was discovered recently by researchers at the University of Toronto.

Twenty years ago, scientists found odd cracks in a tooth from T. Rex’s cousin, Albertosaurus, and they always chalked it up to damage, LiveScience reported. This new study proves that theory wrong. Lead researcher Kirstin Brink studied the teeth from eight different theropods, including the T. rex, and the dinosaurs’ baby teeth.

All of them, including the ones that hadn’t broken through the gums yet, showed signs of this serration. Since the newest teeth — dinosaurs can grow new ones at any time, but it takes about two years — also had this structure, the theory that munching on a tough meal caused the cracks was debunked.

“We proposed a developmental hypothesis that these are structures created when the tooth is first forming,” Brink said. “It actually helps to deepen the serration within the tooth and strengthen each serration and the tooth overall.”

In other words, the cracks weren’t cracks at all, but folds that actually achieved the opposite — they kept a tooth from cracking in the first place.

When a dino like T. rex sat down to dinner, this structure kept them from breaking their ivories on a hard bone. Add in some layers of dentine at the base of each serration, and you have yourself a very strong tooth, indeed.

The unique, protective structure may have been necessary, because dinosaurs like T. rex had to wait so long to get new ones, should the originals be ruined.

The teeth were also very efficient, thanks to these deep folds. The serrated edge was much like a steak knife, puncturing flesh and keeping it steady as they ate.

It was likely these teeth, which sound rather frightening, that helped keep the T. rex at the top of the food chain for 165 million years. After all, what prey could possibly compete with a dino who can boast steak knives for pearly whites?

These days, Komodo dragons are the only animals with this special kind of deadly smile.

[Photo Courtesy Oli Scarff / Getty Images]