The world's first predators had ferocious steak-knife teeth.

Researchers found a dinosaur that walked the Earth between 272 million and 298 million years ago was the "first terrestrial vertebrate to develop serrated ziphodont teeth," a University of Toronto news release reported.

 Ziphodont teeth have serrated edges; this type of tooth would have allowed the dinosaur, dubbed  Dimetrodon, to eat prey large than itself. Most predatory dinosaurs had ziphodont teeth, but this new research shows Dimetrodon developed them

"Technologies such as scanning electron microscope (SEM) and histology allowed us to examine these teeth in detail to reveal previously unknown patterns in the evolutionary history of Dimetrodon," Graduate student an d lead author Kirstin Brink said in the news release.

The Dimetrodon was about four meters long and was king of the food chain during the Early Permian Period. They were the first dinosaurs to develop cusps (" teeth with raised points on the crown, which are dominant in mammals.") The development of Dimetrodon in later species suggests there was a gradual change in the dinosaur's feeding habits.

"This research is an important step in reconstructing the structure of ancient complex communities," Professor Robert Reisz from U of T Mississauga's Department of Biology said in the news release. "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."

The team looked at the Dimetrodon teeth over 25 million years of evolution.

"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," Reisz said. "Teeth fossils have attracted a lot of attention in dinosaurs but much less is known about the animals that lived during this first chapter in terrestrial evolution."