A 31,000-year-old fossil has challenged everything scientists thought about the extinct 'American cheetah' — its DNA and diet tell a surprising story

For thousands of years, a mysterious big cat roamed the grasslands and forests of North America. With long legs and a body built for speed, Miracinonyx trumani eventually became known as the “American cheetah.”

The name seemed to make sense. The extinct predator lived alongside fast-moving prey and had a body shape that invited comparisons with Africa’s famous cheetahs.

But new genetic evidence suggests that the name may have been misleading all along.


Researchers studying ancient DNA from fossils have found that Miracinonyx trumani was much more closely related to modern pumas than to cheetahs. Even more surprisingly, evidence from fossils discovered in Canada's Yukon Territory suggests the extinct cat may have had a far more flexible diet than its nickname implies.

The findings, published in Current Biology, offer a new picture of an Ice Age predator that may have been capable of adapting its hunting strategy to very different environments.

Ancient DNA rewrites the American cheetah's family tree

The discovery began with three fossils recovered from the Yukon that were estimated to be around 31,000 years old.

Because the remains had been discovered so far north, researchers initially suspected they belonged to pumas. Genetic testing, however, produced a very different answer.

The fossils turned out to belong to Miracinonyx trumani.

The team then compared genetic material from the Yukon specimens with DNA from another fossil found in Wyoming. The analysis confirmed that the extinct species' closest living relative is the puma.

The two lineages appear to have separated from their shared ancestor approximately 2.6 million years ago.

Cheetahs, meanwhile, are considerably more distant relatives. The lineage leading to Miracinonyx and modern cheetahs is estimated to have diverged around 4.7 million years ago.

That distinction changes how scientists view an animal that has long been associated with the cheetah family.

Its name may have created the wrong image

Calling Miracinonyx trumani an American cheetah naturally conjures up an image of a specialised speed hunter chasing extremely fast prey across open grasslands.

Modern African cheetahs are famous for precisely that lifestyle, using extraordinary acceleration and speed to pursue prey.

But being built for speed does not necessarily mean Miracinonyx lived in exactly the same way.

Its genetic relationship with pumas suggests a different evolutionary story. Pumas are highly adaptable predators capable of hunting animals ranging from deer and elk to smaller mammals.

The new evidence indicates that Miracinonyx may also have been capable of changing its diet according to what was available in its environment.

That flexibility becomes particularly interesting when researchers look at populations living in the far north.

Yukon fossils reveal an unexpected diet

The Yukon specimens lived in an environment very different from the grasslands where many American cheetah fossils have been discovered.

Researchers wanted to determine what these northern cats actually ate.

To do that, they turned to a chemical clue preserved in their fossilised remains: nitrogen isotopes.

Animals acquire different forms of nitrogen through their diets. As nitrogen moves through a food chain, the heavier isotope becomes increasingly concentrated in predators.

By examining those isotope levels, scientists can estimate an animal's position within an ancient food web.

The results produced a striking contrast.

Fossils from Wyoming showed nitrogen signatures consistent with a terrestrial predator feeding on herbivores.

The Yukon specimens told another story.

Their isotope values were exceptionally high, suggesting that the northern Miracinonyx may have relied heavily on aquatic prey, potentially including fish.

Did this extinct cat actually go fishing?

The evidence does not prove that the American cheetah actively hunted fish.

There are at least two possibilities.

The cats may have caught fish themselves, particularly if they encountered abundant aquatic resources in rivers and other waterways. Alternatively, they could have scavenged fish that had already died or been left behind by other predators.

Either way, the possibility is significant because it shows how dramatically the animal's diet may have changed depending on where it lived.

One of the Yukon fossils was discovered in a cave that also contains numerous Pleistocene fish remains. That does not establish a direct predator-prey relationship, but it provides evidence that aquatic food was available in the same environment.

The findings therefore raise a bigger question about how adaptable Miracinonyx really was.

A flexible hunter may have been hiding behind the “cheetah” nickname

For a large predator, hunting big animals comes with considerable risks.

A failed attack can result in serious injury, while confronting powerful prey can leave a carnivore badly wounded or even dead.

Access to smaller or more abundant food sources can therefore provide an evolutionary advantage.

The Yukon evidence suggests Miracinonyx may have exploited whatever resources its surroundings offered rather than depending exclusively on large terrestrial herbivores.

That would make the extinct cat look much more like an adaptable puma than the specialised African cheetah suggested by its common name.

Paleoecologist Larisa DeSantis, who was not involved in the research, described this potential flexibility as evidence of the animal's ability to adapt to available resources.

The American cheetah lived across a huge area

Miracinonyx trumani survived in North America for millions of years, with evidence placing it across a broad geographic range.

The species lived during the Pleistocene, a period marked by major changes in climate, landscapes and animal communities. Its known fossil record extends from roughly 2.5 million years ago until around 16,000 years ago.

Finding specimens in the Yukon pushes the known northern range of the species further than previously understood.

That geographic expansion matters because animals living at opposite ends of such a large range would have encountered very different prey and environmental conditions.

The new research suggests that the American cheetah may have responded to those differences more effectively than scientists once assumed.

More fossils could reveal how adaptable it really was

The study provides an important piece of the puzzle, but it does not settle every question about Miracinonyx trumani.

Researchers need to examine more fossils from different parts of North America to determine whether the dietary differences seen between Yukon and Wyoming specimens were widespread or represented a particularly unusual northern adaptation.

Future discoveries could reveal whether other populations also relied on aquatic food or whether the Yukon animals were responding to a specific local environment.

Such research could also help scientists understand why the species eventually disappeared.

An extinct predator gets a new identity

The “American cheetah” name is unlikely to disappear overnight. It has been used for decades because of the animal's striking physical resemblance to modern cheetahs.

But genetics tells a more complicated story.

Miracinonyx trumani was not simply a North American version of the African cheetah. Its evolutionary history places it much closer to pumas, while its fossil chemistry suggests that at least some populations could make use of surprisingly different food sources.

The discovery is a reminder that appearance can sometimes tell only part of an animal's story.

What looked like a specialised speed predator may instead have been a versatile North American cat — one capable of changing its diet when its environment demanded it.

And with more fossils still waiting to be examined, scientists may have only begun to uncover how unusual this extinct predator really was.