South America’s largest predator before the dinosaurs

Exquisitely preserved 265-million-year-old fossils unearthed in South America come from a predator which ruled before the “Age of Dinosaurs.”

Pampaphoneus biccai was discovered in the rural São Gabriel region of southern Brazil. It is known from a near-complete skull and other fragments including rib and arm bones. The new species is described in a paper published in the Zoological Journal of the Linnean Society.

Palaeontologists believe Pampaphoneus would have been a skilled hunter, filling a similar ecological niche as today’s big cats, feeding on small and medium animals.

The creature lived in a period of Earth’s history known as the Permian (299–252 million years ago). At the time, all of Earth’s continents were merged into the region known as Pangaea.

This epoch saw the diversification two types of land vertebrate: sauropsids (the group which includes reptiles, dinosaurs and birds) and a group known as synapsids (a group which today includes humans and all other mammals).

Synapsids during the Permian were made up of what used to be referred to as mammal-like reptiles. More accurately, these creatures were not reptiles at all, but represented the evolutionary ancestors of mammals. They are sometimes called “stem mammals” or “proto-mammals.”

Pampaphoneus belongs to the dinocephalian clade of therapsids (a subgroup of synapsids). It is, therefore, more closely related to humans than to dinosaurs or reptiles.

The Permian ended with the largest extinction event in Earth’s history. An estimated 86% of all animal species were wiped out.

After the Permian extinction came the dawn of the Age of Dinosaurs.

South America is famous for its giant dinosaurs. Among them were some of Earth’s largest ever predators including Giganotosaurus which, at 13 metres in length and about 8 tonnes, would have rivalled T. rex for size.

Dinocephalians were one of the major groups of large land animals before the dinosaurs came onto the scene. They are well known from fossils found in South Africa and Russia but are rare in other parts of the world. Pampaphoneus is the first species of dinocephalian found in Brazil.

Their name means “terrible head” in Greek owing to their thick cranial bones.

“The fossil was found in middle Permian rocks, in an area where bones are not so common, but always hold pleasant surprises,” says lead author Mateus A. Costa Santos, a graduate student in the Brazil’s Federal University of Pampa.

It is the second Pampaphoneus skull found in South America, but is much larger than the first at nearly 40 centimetres.

“Finding a new Pampaphoneus skull after so long was extremely important for increasing our knowledge about the animal, which was previously difficult to differentiate from its Russian relatives,” Santos says.

An unidentified third fossil represents an individual which could be up to two times larger than even the new specimen.

Researchers believe Pampaphoneus could have grown to nearly 3 metres in length and weighed in at about 400kg.

“It was the largest terrestrial predator we know of from the Permian in South America,” says Professor Felipe Pinheiro. “The animal had large, sharp canine teeth adapted for capturing prey. Its dentition and cranial architecture suggest that its bite was strong enough to chew bones, much like modern-day hyenas.”