DNA Reveals Link Between Saber-Toothed Cats and Domestic Felines

Reconstructed skeleton of a Saber-tooth Cat (Smilodon californicus)

Saber-toothed cats were among the animal kingdom’s most formidable predators. Their sharp, dagger-like teeth could grow up to seven inches long, and were likely used to slay everything from enormous woolly mammoths to rhinos.

Their evolutionary history has been shrouded in mystery, but a new genetic analysis published in the journal Current Biology reveals many surprising finds. One is the link between these stealthy carnivores and animals that are now residing in many households the world over.

“The two saber-toothed cat mitochondrial lineages we investigated — Smilodon and Homotherium — diverged from all living cat-like species around 20 million years ago,” lead author Johanna Paijmans told Seeker, clarifying that the big, ancient cats were indeed related to today’s common domesticated cats.

Paijmans, a researcher at the University of Potsdam’s Institute for Biochemistry and Biology, has always been interested in extinct mammal lineages. When she was asked to perform DNA analysis on saber-tooth cat remains starting about 5 years ago, she jumped at the chance.

The story behind this particular study began long before then, however.

“It all started with the recovery of a 28,000-year-old Homotherium fossil from the North Sea by Jelle Reumer and colleagues in 2000,” Paijmans explained.

Artist depiction of a Homotherium

Homotherium became extinct in Africa about 1.5 million years ago. It was thought to have gone extinct in Europe 300,000 years ago, so scientists were puzzled by the estimated age of the North Sea fossil.

Paijmans, senior author Michael Hofreiter, and their team analyzed this big cat’s complete mitochondrial genome and compared it to that of Smilodon, the world’s best-known saber-toothed cat that became extinct around 10,000 years ago.

“Our results prove that Homotherium did exist in Europe around 28,000 years ago,” Paijmans said.

“With the current knowledge,” she continued, “it’s not clear whether Homotherium did exist (in Europe) between 300,000 and 30,000 years ago at very low population densities, or if Homotherium re-dispersed from North America during the Late Pleistocene after the earlier populations had already gone extinct.”

The date of Homotherium’s presence in Europe opens up yet another intriguing mystery.

“When the first anatomically modern humans migrated to Europe, there may have been a saber-toothed cat waiting for them,” she said.

There is no question that Neanderthals and other early hominids in Europe and Asia lived in regions where saber-toothed cats lurked.

A few years ago, a team of archaeologists working at the Schöningen site in north-central Germany found saber-toothed cat remains next to an ancient stash of weapons. They included several wooden spears, a lance, a double-pointed stick and another stick that was burnt.

It is then possible that early humans waged battles with saber-toothed cats, attempting to either kill or scare them off with torches and their weapons. Since both humans and these predators were drawn to caves, their paths could easily have crossed often, with each group going after similar prey — not to mention each other.

Saber-toothed cats might have even affected early human migration routes, but more evidence is needed to clarify how our human ancestors could have interacted with these fierce felines.

Paijmans said we need to re-think how and where Homotherium lived during the Late Pleistocene, as it occurred in Europe much later than we previously thought. “This,” she said, “can open up new questions about its extinction that can be addressed in future studies.”

In short, it is now possible that anatomically modern humans migrating from Africa could have killed off this species of saber-toothed cat, and possibly others.

A homotherium fossil recovered from the North Sea

Yet another surprising finding from the study is the conclusion that Smilodon and Homotherium were not very closely related.

“In terms of their mitochondrial DNA, these two saber-toothed cats are more distant from each other than tigers are from housecats,” Paijmans said.

After the cats diverged from their common ancestor, they traveled and evolved into distinct forms. Nonetheless, they shared the similar, very toothy dentition that was lost when they went extinct.

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