Sawlike teeth gave T-Rex the edge over other dinosaurs


The deeply serrated or sawlike teeth gave carnivorous theropods such as T. rex and Allosaurus the edge over other dinosaurs enabling them to easily tear through the flesh and bone of their prey, a new study has revealed.

Tyrannosaurus rex and its fellow theropod dinosaurs prospered during their peak and preyed over other dinosaurs and the special structure of their teeth played a role, researchers from the University of Toronto Mississauga (UTM) have revealed.

Kirstin Brink, a post-doctoral researcher in the Department of Biology at UTM and her colleagues determined that this deeply serrated–or sawlike–tooth structure is uniquely common to carnivorous theropods such as T. rex and Allosaurus, and even one of the first theropods, Coelophysis.

Though other dinosaurs and few other animals had teeth that were superficially similar, the special arrangement of tissues inside the tooth in T-Rex strengthened and improved the function of the teeth. Further, the deep serrations made them much more efficient at chomping on bones and ripping flesh of larger animals and reptiles, and allowed them to prosper for million of years as fearsome, top predators.

Komodo dragon, native to Indonesia, is the only reptile living today that has the same superficial tooth structure.

Researchers say that though all animal teeth are made from the same building blocks, but the way the blocks fit together to form the structure of the tooth greatly affects how that animal processes food.

“The hidden complexity of the tooth structure in theropods suggests that they were more efficient at handling prey than previously thought, likely contributing to their success”, Brink said.

Researchers say that the unique arrangement of tooth tissues wasn’t in response to these carnivores chewing hard materials. They determined this by examining samples of dinosaur teeth that had not yet broken through the gums, as well as samples from mature dinosaur teeth. Unlike humans, reptiles grow new teeth throughout their lifetimes.

“What is startling and amazing about this work is that Kirstin was able to take teeth with these steak knife-like serrations and find a way to make cuts to obtain sections along the cutting edge of these teeth,” said Reisz. “If you don’t cut them right, you don’t get the information.

“This brought about a developmental explanation for the tooth formation; the serrations are even more spectacular and permanent.”

Brink and colleagues used a scanning electron microscope – a very powerful microscope — and a synchrotron – a microscope that allows the user to understand a substance’s chemical composition — to do a thorough examination and analysis of tooth slices from eight carnivorous theropods, including T. rex, Allosaurus, Coelophysis and Gorgosaurus. The samples came from various museums, including the ROM, the Canadian Museum of Nature in Ottawa, and the Royal Tyrrell Museum in Alberta.

The research is published in the journal Scientific Reports.