Fossils of the saber-toothed predator that gave rise to all discovered mammals

Scientists have discovered 280-million-year-old fossil remains of a predator from which all mammals evolved.

This ancient animal, which does not yet have a species name, is a member of an evolutionary group known as the gorgonopsians – a distant relative of mammals – which an extinct clade of sabre-toothed therapsids.

They were ultimately four-legged, somewhat reptilian animals gave rise to mammals about 200 million years ago.

Co-author Ken Angielczyk said: ‘Gorgonopsians are more closely related to mammals than to other living animals.

“Although they are not our direct ancestors, they are related to species that were our direct ancestors.”

The newly discovered fossils – including fragments of the skull, vertebrae and ribs of a very well-preserved femur – belonged to a vaguely dog-like saber-toothed predator that researchers believe is the oldest therapsid ever discovered.

Until now, the oldest known gorgonopsians lived about 265 million years ago, but these fossils are about 15 million years older.

They were excavated on Mallorca, a Spanish island in the Mediterranean Sea. When gorgonopsians still roamed the Earth, Mallorca was part of the supercontinent Pangea.

Gorgonopsians were vaguely dog-like saber-toothed predators that roamed the Earth until 280 million years ago, this new discovery suggests

“If you saw this animal walking down the street, it would look a bit like a medium-sized dog, maybe about the size of a husky,” Angielczyk, a paleobiologist at the Field Museum in Chicago, said in an interview. statement.

‘But that wouldn’t be quite right. ‘He had no fur and he wouldn’t have had dog-like ears. But it is the oldest animal scientist ever to have long, blade-like canines,” he added.

The saber teeth suggest this animal was an apex predator when it was alive, confirming its carnivorous diet.

The presence of a nearly complete leg also allowed researchers to surmise how the animal moved.

Analysis of the leg remains suggested that gorgonopsians “moved in a manner intermediate between reptiles and mammals,” which was more efficient at walking and running than at true reptilian movements.

Angielczyk and colleagues from the Field Museum worked with researchers from the Catalan Institute of Paleontology Miquel Crusafont in Barcelona, ​​Spain to excavate and analyze the fossils.

They published their findings today in the journal Nature communication.

The Gorgonopsian remains were recovered from a site in the Mallorcan town of Banyalbufar.

The newly discovered fossils include fragments of the skull, vertebrae and ribs of a very well-preserved femur.

The presence of a nearly complete leg also allowed researchers to surmise how the animal moved

The saber teeth suggest this animal was an apex predator when it was alive, confirming its carnivorous diet

‘The large number of bone remains is surprising. We found everything from fragments of the skull, vertebrae and ribs to a very well-preserved femur,” said lead author Rafel Matamales, research fellow at the Catalan Institute.

“When we started this excavation, we never actually imagined that we would find so many remains of an animal of this type in Mallorca,” he added.

Moreover, the researchers were surprised to find these types of specimens in the Balearic Islands, as the known remains of gorgonopsians had until now been found in very high latitudes such as Russia or South Africa.

But this isn’t the first time these tiny Spanish islands have produced groundbreaking fossil discoveries.

The world’s oldest mosquito was found there, as well as nearly thousands of species of ammonoids, or cephalopods related to squids, ancestors of horses and hippos, giant sharks and large coral reefs, the researchers said.

The fact that this newly discovered gorgonopsian is tens of millions of years older than its closest relatives changes scientists’ understanding of when therapsids evolved, the researchers concluded in the statement.

And because therapsids are the ancient ancestors of mammals, this finding also clarifies when and how humans evolved.

‘Before the time of the dinosaurs, there was an era of ancient mammalian relatives. Most of those ancient mammal relatives looked very different from what we think mammals look like today,” Angielczyk said.

‘But they were very diverse and played many different ecological roles. The discovery of this new fossil is a new piece of the puzzle for mammalian evolution.”