‘Dog-Like’ Fossil Discovery May Be Oldest Known Saber-Toothed Animal

Paleontologists have revealed what may be the earliest known saber-toothed animal to have ever lived—a predator that roamed our planet before the age of the dinosaurs.

In a study published in the journal Nature Communications, a team of researchers describe a previously unknown prehistoric creature that would have been vaguely dog-like in appearance, albeit with noticeable differences.

“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,” study co-author Ken Angielczyk, with the Field Museum of Natural History in Chicago, said in a press release.

Among its most distinctive features were a set of very long, blade-like, canine teeth, which suggest the animal was a “top predator” in its day, according to Angielczyk.

The creature—which long predates the first true mammals, as well as the dinosaurs—is described based on a fossil specimen found on the Spanish island of Mallorca, located in the Mediterranean Sea.

Remarkably, the fossil seems to date to around 280-270 million years ago—when Mallorca formed part of the supercontinent Pangea—making it, most likely, the oldest known member of a group of extinct animals known as the gorgonopsians. These are prehistoric mammal relatives that lived during the Permian period (around 299-252 million years ago) of Earth’s history.

Modern mammals belong to a larger group of tetrapods (four-limbed animals with backbones) called Synapsida. Mammals (known scientifically as Mammalia) are the only living synapsids, having first evolved around 200 million years ago. But there are many extinct groups of so-called non-mammalian synapsids.

“These are also members of the synapsid lineage, and they are more closely related to modern mammals than to animals like reptiles, birds, or amphibians, but they fall outside of Mammalia proper and don’t have all the features of modern mammals,” Angielczyk told Newsweek.

“Gorgonopsians are one of these extinct groups of non-mammalian synapsids, that lived during the Permian… They were important predators at that time, but they’re a side branch of the synapsid family tree and they don’t have any living descendants—i.e., they are not direct ancestors of mammals.”

The oldest known gorgonopsians prior to this study are thought to have lived around 265 million years ago. But the newly uncovered specimen appears to predate this time.

“The most interesting thing about the specific specimen that we describe is its age. As we say in the paper, it is pretty certainly the oldest known gorgonopsian,” Angielczyk said.

Gorgonopsians are the first group of tetrapod predators we know of in the fossil record to evolve saber-tooth characteristics—i.e., very large, blade-like, serrated canines. The Mallorca specimen may represent the earliest known example of this group—and thus, the first saber-toothed animal on our planet—although there is some uncertainty regarding the age.

“The age uncertainty makes it a little hard to be completely definitive that it’s the oldest saber-toothed animal found so far because there’s a chance it might be about the same age as the other oldest gorgonopsians found in the fossil record,” Angielczyk said. “However, assuming the evidence suggesting an older age is correct, our specimen would be older than the previously oldest known gorgonopsians.”

The creature is also likely the oldest known member of a subgroup of synapsids called Therapsida, which includes mammals and a subset of non-mammalian synapsids that are relatively closely related to mammals. According to the authors, the latest find casts new light on the evolutionary history of the therapsids.

“There is a big time gap in the fossil record of therapsids, between when they are predicted to have evolved based on our knowledge of relationships of synapsids and when they actually show up in the fossil record, and the new specimen helps to fill in part of that gap,” Angielczyk said.

“I don’t think a lot of people realize that before the age of dinosaurs, there was a period of time when ancient mammal relatives were the dominant animals on land. Our gorgonopsian lived during that time, and was one of those ancient mammal relatives.”

Researchers found a surprisingly large number of bone remains of the gorgonopsian during their investigations in Mallorca.

“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,” study first author Rafel Matamales, curator of the Museu Balear de Ciències Naturals, said in the press release.

Despite this, the specimen was too fragmentary for the researchers to determine whether it represents a member of a known gorgonopsian species or if it represents an entirely new species. As a result, the specimen has not yet been assigned a species name.

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