Some of the reptiles of Mesozoic era relied mainly on plant-dominated diets: study

Crocodiles are sometimes described as living fossils for their close resemblance to their forebears who roamed the earth during the age of the dinosaurs.

But if you happened to find yourself a time machine that sent you back to the Mesozoic Era, not all the crocodiles you would come across would size you up as a tasty meal.

That’s according to a new study published in Cell Press on Thursday that fed high-resolution scans of 146 teeth from 16 extinct species into a computer model and determined that, unlike their modern progeny who are known for their ferocity, some early crocodyliforms were an altogether more peaceful lot.

‘Tooth complexity’

“What is really fascinating about this is a lot of these teeth are unlike anything we see today,” Keegan Melstrom, a doctoral student at the University of Utah, who conducted the research along with his supervisor Randall Irmis, said.

To determine what tooth complexity reveals about diet, Mr. Melstrom relied on previous work on heterodonty in mammals, and his own earlier findings about teeth differences in reptiles.

“Some were similar to living crocodylians and were primarily carnivorous, others were omnivores, and still others likely specialised in plants,” he said, adding that they lived on different continents and at different times.

What remains a mystery, however, is what made crocodyliforms eat plant-dominated diets, and why they disappeared.