'Steak knife' teeth made early dinosaurs top food chain predators

TORONTO, Feb. 7 (UPI) -- The first top carnivore predator to walk on land developed "steak-knife" teeth allowing it to eat prey much larger than itself, Canadian scientists say.

Dimetrodon, a dinosaur carnivore that lived 298 million to 272 million years ago, was the first terrestrial vertebrate to develop what are called ziphodont teeth, serrated like a steak knife, researchers at the University of Toronto reported Friday.

Such teeth produced a more efficient bite, and Dimetrodon evolved them some 40 million years earlier than theropod meat-eating dinosaurs like T. Rex, they said.

"The steak knife configuration of these teeth and the architecture of the skull suggest Dimetrodon was able to grab and rip and dismember large prey," UT biology Professor Robert Reisz said.

Dimetrodon, which could grow to lengths of more than 13 feet, is seen as the top predator in the terrestrial food chain in the Early Permian Period, the researchers said.

"Teeth tell us a lot more about the ecology of animals than just looking at the skeleton," Reisz said.

"We already know from fossil evidence which animals existed at that time but now with this type of research we are starting to piece together how the members of these communities interacted."