By Stephen Beech
The fossilized remains of the oldest known animal with “saber teeth” have been discovered on a Spanish holiday hotspot.
The roughly three feet long “vaguely dog-like” predator – one of the oldest-known close cousins of modern mammals – inhabited Mallorca before it was an island around 270 million years ago, say scientists.
They explained that the first true mammals evolved roughly 200 million years ago, during the early days of the dinosaurs.
But mammals are the last surviving members of an older group, called the therapsids.
At first glance, many therapsids weren’t obviously mammal-like, but they also had subtle features recognized in mammals today, such as a hole on the sides of their skull for the jaw muscle to attach.
In a new paper, published in the journal Nature Communications, scientists revealed the discovery of a fossil therapsid that’s the oldest of its kind, and maybe the oldest therapsid ever discovered.
They say the new fossil, which doesn’t have a species name yet, is a member of a group called the gorgonopsians.
Study co-author Dr. Ken Angielczyk, of the Field Museum in Chicago, said: “Gorgonopsians are more closely related to mammals than they are to any other living animals.
“They don’t have any modern descendants, and while they’re not our direct ancestors, they’re related to species that were our direct ancestors.”
Until now, the oldest known gorgonopsians lived roughly 265 million years ago.
But the new fossil is dated to between 270 and 280 million years ago.
Study senior author Dr. Josep Fortuny, of the Institut Català de Paleontologia (ICP) in Spain, said: “It is most likely the oldest gorgonopsian on the planet.”
The previously known remains of gorgonopsians prior to the new discovery belonged to very high latitudes such as Russia or South Africa.
Its age also surprised the research team.
Dr. Rotuny said: “The one we found in Mallorca is at least 270 million years old, and the other records of this group worldwide are, at the very least, slightly younger.”
Àngel Galobart, researcher at the ICP, said: “We know that this is a carnivorous animal, a characteristic shared by all gorgonopsians worldwide.
“The saber teeth are a common feature in large predators of ecosystems, and what we have found was likely one in the environment in which it lived,”
The research team explained that Mallorca, at the time of the gorgonopsians, was part of the “supercontinent” of Pangea.
Study first author Rafel Matamales, research associate at the ICP, said: “The large number of bone remains is surprising.
“We have found everything from fragments of skull, vertebrae, and ribs to a very well-preserved femur.
“In fact, when we started this excavation, we never thought we would find so many remains of an animal of this type in Mallorca,”
The plethora of bones allowed the researchers to reconstruct what the animal looked like and a little about its life.
Dr. Angielczyk said: “If you saw this animal walking down the street, it would look a little bit like a medium-sized dog, maybe about the size of a husky, but it wouldn’t be quite right.
“It didn’t have any fur, and it wouldn’t have had dog-like ears.
“But it’s the oldest animal scientists have ever found with long, blade-like canine teeth.”
He said the teeth suggest that this gorgonopsian was a top predator in its day.
The fact that the new gorgonopsian predates its closest relatives by tens of millions of years changes scientists’ understanding of when therapsids evolved, an important milestone on the way to the emergence of mammals.
Dr. Angielczyk said: “Before the time of dinosaurs, there was an age of ancient mammal relatives.
“Most of those ancient mammal relatives looked really different from what we think of mammals looking like today.
“But they were really diverse and played lots of different ecological roles.”
He added: “The discovery of this new fossil is another piece of the puzzle for how mammals evolved.”
