Careful, the big kitty bites! Stealthily stalking prey amid the prehistoric grasslands of what's now considered Eastern Oregon, a new species of giant saber-toothed cat that lived in North America some 5 million to 9 million years ago has been identified by a team of paleontologists from Gonzaga University and Ohio State University.
This fearsome carnivore tipped the scales at between 600 and 900 pounds and was capable of taking down huge mammals weighing up to 6,000 pounds.
According to a research paper published last week in the Journal of Mammalian Evolution, this new-found specimen provides clear evidence for a diverse range of predator fauna existing during the late Miocene of the continent that included some of the biggest felids in Earth's history.
The sabre-toothed cat was part of an early evolutionary branch that went extinct roughly 10,000 years ago, where today's house cats are an entirely different evolutionary offshoot that emerged later. Sabre-toothed cats, similar to lions, were quite social animals that hunted for their meals and existed amongst other members of the same species.
“We believe these were animals that were routinely taking down bison-sized animals,” said study co-author Jonathan Calede, an assistant professor of evolution, ecology and organismal biology at The Ohio State University’s Marion campus. “This was by far the largest cat alive at that time.”
Calede collaborated with John Orcutt, assistant professor of biology at Gonzaga University, to complete the revealing study. Several years ago, Orcutt happened upon a large upper arm bone (humerus) specimen that had been labeled as a cat in the University of Oregon Museum of Natural and Cultural History collection.
After the time-consuming process of comparing seven uncategorized fossil specimens with previously identified fossils and bone samples from around the globe, they concluded that this new species is an ancient relative of the well-known saber-toothed cat Smilodon, whose fossil was found in California's La Brea Tar Pits.
This Oregon specimen was originally excavated on the traditional lands of the Cayuse Indians, a tribe aligned with the Umatilla and Walla Walla in the Confederated Tribes of the Umatilla Indian Reservation.
In recognition of its Native American heritage, Calede and Orcutt worked with the Tamástslikt Cultural Institute to christen the new species Machairodus lahayishupup. Machairodus is a genus of large saber-toothed cats that roamed ancient Africa, Eurasia, and North America. In the Old Cayuse language, Laháyis Húpup translates out to “ancient wild cat.”
“One of the big stories of all of this is that we ended up uncovering specimen after specimen of this giant cat in museums in western North America,” Orcutt said. “They were clearly big cats. We started with a few assumptions based on their age, in the 5 1/2 to 9 million-year-old range, and based on their size, because these things were huge.
“What we didn’t have then, that we have now, is the test of whether the size and anatomy of those bones tells us anything – and it turns out that yes, they do.”
The biggest of the seven Machairodus lahayishupup humerus fossils used for the analysis was over 18 inches long, larger than the average modern adult male lion’s humerus of 13 inches.
As part of their journey of discovery, Calede and Orcutt took numerous field trips to museums in the U.S., Canada, and France to acquire photos of forearm specimens of lions, pumas, panthers, jaguars and tigers, including fossils of previously catalogued extinct big cats for comparison.
Calede then employed software to place landmark indicators on each digitized sample that created a model of each specimen’s elbow when gathered together.
“We found we could quantify the differences on a fairly fine scale,” Calede noted. “This told us we could use the elbow shape to tell apart species of modern big cats.
“Then we took the tool to the fossil record – these giant elbows scattered in museums all had a characteristic in common. This told us they all belonged to the same species. Their unique shape and size told us they were also very different from everything that is already known. In other words, these bones belong to one species and that species is a new species.”