Skull of veggie-eating animal from 307 million years ago found

A 307-million-year-old skull discovered in Canada may have belonged to one of the earliest known vegetarian animals, scientists say.

Paleontologists - scientists who study fossils - found the skull inside a fossilized tree stump in Nova Scotia, Canada. It belonged to a Tyrannoroter herberti - one of the earliest known land animals.

"This is one of the oldest known four-legged animals to eat its veggies," said Arjan Mann from the Field Museum in Chicago, who is one of the experts behind the study.

While we have lots of plant-eating animals on Earth today, that wasn't the case millions of years ago.

Scans of its skull revealed that Tyrannoroter was one of the first animals to figure it didn't have to chomp its neighbour to survive.

It's thought it belonged to a group of early members of four-legged land animals called tetrapods, that were forerunners of the amphibians, reptiles, mammals and birds that exist now.

The earliest tetrapods were meat-eaters. Over time, some apparently began eating insects and then, as Tyrannoroter shows, decided eating vegetation was the way to go.

Tyrannoroter heberti had a triangle-shaped skull that had plenty of room for large cheek muscles, perfect for eating tough plant material.

Its teeth were also shaped to crush and grind a lot of veggies - although it probably would have snaffled a few small insects as well.

Although researchers have only discovered the skull, they estimate Tyrannoroter was about 12 inches (30.5 cm) long, with a stocky build.

It might have looked a bit like a lizard, scientists say, but is not actually included in that class of animals.

It's categorized as part of a group called microsaurs, small animals that roamed the Earth well before gigantic dinosaurs made their appearance.