Meat-eating dinosaurs: special serrations kept teeth extra sharp

Meat-eating dinosaurs have serrated edges on their teeth, which is nothing new. However, the extent and complexity of those serrations has only just recently been observed, with researchers noting that the serrations include "deep folds" where each serrated part begins. These folds were originally thought to be cracks resulting from the force of the dinosaur's biting, but a more extensive look at teeth from multiple creatures has revealed the special serrations were common among flesh-eating dinosaurs, serving to keep their teeth as sharp as possible for as long as possible.The discovery was made by Kirstin Brink, a paleontologist with the University of Toronto, and her colleagues. It is well known that theropod dinosaur teeth have a series of bumps — serrations like in a steak knife — up the side. The researchers looked at the teeth under a microscope, however, and found that each of those serrated bumps meet the bumps next to it with a deep fold. Some researchers believed those bumps to be small cracks.

Brink and the team, however, looked at teeth from theropods spanning a wide gamut — big and small, young and old — and discovered the same deep folds, including in teeth that hadn't yet broken through the gum line. This means such folds were a common feature of the teeth rather than a result of damage.

No other carnivore has been found to possess the same deep folds, which are thought to have been a contributing factor to the success of theropods during the Mesozoic. The bumps both strengthened and kept the teeth sharp, ensuring the dinosaurs had them available for as long as possible before losing them and, slowly, growing a replacement tooth.

SOURCE: National Geographic