Oldest land predators killed prey with 'steak-knife' teeth

Hold your breath. The oldest land predators on earth were able to grab, rip and dismember large prey - thanks to 'steak-knife' teeth they got, reveals research.

Dimetrodon, a carnivore that walked on land between 298 million and 272 million years ago, was the first terrestrial vertebrate to develop serrated ziphodont teeth with steak-knife configuration.

Ziphodont teeth, with their serrated edges, produced a more-efficient bite and would have allowed Dimetrodon to eat prey much larger than itself, said a study by University of Toronto Mississauga.

"New technologies and histology allowed us to examine these teeth in detail to reveal previously unknown patterns in the evolutionary history of Dimetrodon," said lead author Kirstin Brink along with professor Robert Reisz from U of T Mississauga's department of biology.

While most meat-eating dinosaurs possessed ziphodont teeth, fossil evidence suggests serrated teeth first evolved in Dimetrodon some 40 million years earlier than theropod dinosaurs, Brink added.

The four-meter-long Dimetrodon is considered to be the forerunner of mammals.

Dimetrodon had a diversity of previously unknown tooth structures and were also the first terrestrial vertebrate to develop cusps - teeth with raised points on the crown, which are dominant in mammals.

The study also suggests ziphodont teeth were confined to later species of Dimetrodon, indicating a gradual change in feeding habits.

"This research is an important step in reconstructing the structure of ancient complex communities," Reisz said.

With this type of research, researchers are starting to piece together how the members of these communities interacted, said the study published in Nature Communications.