A new species of bear dog has just been found by paleontologists and was named Tartarocyon. “Bear dogs” were one of the extinct species of carnivores. They were ferocious hunters that prowled North America, southern Africa, Asia, and Europe over 7.5 million years ago. They had a powerful jaw designed to rip the flesh from the bones of their prey.
With the discovery of a jawbone of one of these extinct animals in the European Pyrenees mountain region, researchers can now better understand how dangerous bear dogs were and confirm their theory that they were widespread globally before their extinction.
While bear dogs, a genus of ancient land-based predators in the family Amphicyonidae, do not belong to either the dog family (Canidae) or the bear family (Ursidae), they share many physical characteristics with animals from both groups. The fossilized lower jawbone belongs to a new species of bear dog, possibly even a new genus. The jaw bone was around 8 inches or 20 centimeters long.
Why the name Tartarocyon?
The bear dogs were given the name Tartarocyon in honor of Tartaro, a terrifying one-eyed monster from Basque mythology who is said to have lived in Béarn in the late eighth century B.C., in the southwest of France, where the fossil was found.
The fossil was found buried in a marine sedimentary area rich in ancient shells and other fossils. This is on the northern edge of the Pyrenees, in a remote location that, during the Miocene, was bordered to the north and south by a sea that covered much of southwest France.
The features
The jawbone’s teeth are what make it most “striking.” This is according to the lead scientist, Floréal Solé, a paleontologist with the Royal Belgian Institute of Natural Science. She said this in an email to Live Science. The scientists reported in a new study that a fourth lower premolar that had never been observed in the group previously suggested to the scientists that the fossil belonged to a new genus and species and hinted that it was probably a “bone-crushing mesocarnivore,”

Bear dogs possessed relatively long snouts and legs, similar to many dogs. However, they were flat-footed and heavy-bodied like bears. During the Miocene Epoch, they existed between 23 million to 5.3 million years ago. The animals sizes varied, as they weighed between 20 pounds (9 kilograms) and 705 pounds (320 kilograms). Researchers had estimated that Tartarocyon was one of the larger species, weighing about 441 pounds or 200 kilograms
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Paleontologists are doubtful of its connection with other animals
Paleontologists are unsure whether bear dogs may or may not be closely related to other animal families. According to Sole, “based on the divergent viewpoints of the paleontologists, some claimed that the Amphicyonids were phylogenetically connected to canids (wolves, dogs, foxes, and jackals, while others decided that these animals were not related to the ursids (bears and pandas).”

A fourth premolar can be found in Tartarocyon’s fossilized jawbone
Solé explained that the discovery of a novel premolar structure in a bear dog was “extremely exciting.”In addition to suggesting the carnivore could crush bones, this raises concerns about how this species’ evolution may have diverged from that of the rest of the group. Perhaps it took place in a region where populations were geographically separated. She explained further that “Tartarocyon may belong to a branch of the European Amphicyonids that evolved locally due to the original morphology of its teeth.”

Bastien Mennecart, a paleontologist at the museum and a co-author of the paper, said that researchers from the Natural History Museum Basel in Switzerland used scanning technologies and digital reconstructions to transform the newly discovered jaw into a “3D puzzle.”
Mennecart wrote in an email to Live Science, “The jawbone is almost complete and well-preserved in 3D: the small premolars are also preserved.” He continued saying, “The only missing pieces correspond to the two hammer blows used to collect the sediment.”
Since it is the first Amphicyonidae fossil discovered there, bear dogs may have moved even farther across Europe than previously believed. This broadens the Amphicyonids’ geographic range during the Miocene, according to Solé. Every discovery, even a single tiny tooth, is significant. The findings were reported in the journal PeerJ Life & Environment on June 15.
Featured image: Tartarocyon reconstruction by Denny Navarra. Licensed under CC BY 4.0