Four ancient genomes reassign the 'American cheetah' to the puma branch
Three Yukon fossils and one from Wyoming place Miracinonyx trumani beside the puma rather than the cheetah. Nitrogen isotopes put the northern animals near the top of a fish food chain far above the old known range.
The Scientist · Science desk
What happened
- A UC Santa Cruz-led team published nuclear paleogenomes and stable isotope data from Miracinonyx trumani in Current Biology on Sept. 4, using fossils recovered as far north as the Yukon.
- The Yukon material pushes the species' known range 20 degrees of latitude farther north than the fossil record previously supported.
- Nitrogen isotopes read the Wyoming animal as a terrestrial carnivore eating herbivores, while the Yukon animals sat at heavy-nitrogen levels comparable to marine carnivores such as orcas.
- High-coverage genomes from fossils 23,000 to 31,000 years old carry loss-of-function mutations in circadian rhythm genes, which the authors read as adaptation to Arctic light cycles.
- Both the Wyoming and Yukon animals had low genetic diversity, a pattern the authors attribute to a slow decline across the Pleistocene rather than inbreeding or a sharp bottleneck.
Why it matters
- What doesn't add up contradiction The university's account describes cats that specialized in eating fish, while Science News reports the team cannot yet say whether the Yukon animals hunted fish or scavenged carcasses on riverbanks; the isotopes pin trophic level, and the behaviour behind it stays open.
- What it sets up precedent A bone already filed as puma turned out to be a different genus once sequenced, which makes every unsequenced high-latitude felid identification a softer claim than its catalogue label implies.
- What's now possible capability Genomes at this coverage from 23,000-to-31,000-year-old bone let phylogeny and diet be tested on single specimens, in a range where skeletal shape had been converging on the wrong answer.
- What it limits constraint The case limits the usual shortcut from low genetic diversity to extinction risk: senior author Beth Shapiro says the decline was gradual, not driven by low diversity or a bottleneck.
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The reclassification rests on four individuals: three specimens from Bluefish Caves and Upper Quartz Creek in the Yukon, plus one from Natural Trap Cave in Wyoming [6]. Four genomes carry the revision [23]. The Yukon bones were recovered in the Tr'ondek Hwech'in and Vuntut Gwitchin Traditional Territories [19].
The team did not set out to redraw the cat family tree. It wanted to confirm what three roughly 31,000-year-old Yukon fossils were, and those had been tentatively logged as pumas precisely because they turned up so far north; the sequences came back as Miracinonyx trumani, and Molly Cassatt-Johnstone told Science News that everything else followed from there [14]. The prior that failed was geographic as much as anatomical.
Divergence dates put the split from pumas near 2.6 million years ago [2] and the split from cheetahs near 4.7 million [3], leaving about 2.1 million years between the two branch points [22]. The slender frame is read as convergent evolution [10]. The pronghorn argument deserves more care than the nickname invites: its "ghosts of predators past" version holds that the pronghorn's sprint, close to 90 kilometers per hour [9], evolved against a cheetah-like pursuer [8]. Removing the cheetah relationship does not remove the running, and the same work describes an animal capable of terrestrial pursuit as well as grasping prey with powerful forelimbs [11]. What the genome withdraws is permission to read the animal's ecology off its name, which is close to how Cassatt-Johnstone frames it [20].
Nitrogen isotopes answer a narrow question: how many steps up a food chain an animal sat, not what was on the plate or how it got there [13]. Salmon in particular is an inference from anadromy [5] and from the many Pleistocene fish fossils in one of the same Yukon caves [26]. Larisa DeSantis of Vanderbilt, who was not part of the study, notes the payoff of exploiting an abundant prey resource that does not injure the hunter [24].
That leaves the two-ended ecology, which co-author Matthew Wooller of the University of Alaska Fairbanks describes as uber-specialization at opposite ends of a huge range [12], resting on one Wyoming genome against three from the Yukon [6]. More specimens across the range, including south of Wyoming, are what the researchers say would show how adaptable the species really was [25], and that is the number that decides whether this is a species-wide flexibility or three animals near a good fishing spot.
What to watch
- Whether other labs re-sequence far-north felid fossils currently catalogued as puma, the same mistake this study corrected in reverse.
- Whether wider felid sampling ties the inactivated sour-taste receptor gene to specialized diets, or shows it is simply ancestral across cats.
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Reality
- Evidence72
- Adoption22
- Hype gap+18
- Incentives62
- Confidence74
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- [1]
A study led by researchers at the University of California, Santa Cruz analyzed nuclear paleogenomes and stable isotopes from Miracinonyx trumani fossils found as far north as the Yukon, published Sept. 4 in Current Biology.
- [2]
Genomic data show Miracinonyx trumani was a sister species to the modern puma, having diverged from that lineage roughly 2.6 million years ago.
- [3]
Miracinonyx trumani and cheetahs split roughly 4.7 million years ago.
- [4]
The findings reveal that the species' range extended 20 degrees of latitude farther north than previously recognized.
- [5]
Southern populations in regions such as Wyoming and Florida lived as generalist predators in temperate grasslands, while northern counterparts in the Arctic Yukon were tertiary consumers, likely specializing in anadromous fish such as salmon.
- [6]
Three new specimens came from Bluefish Caves and Upper Quartz Creek in Yukon Territory; ancient DNA from those specimens, plus DNA from another M. trumani fossil from Natural Trap Cave in Wyoming, established the puma relationship.
- [7]
Cassatt-Johnstone said the team found loss-of-function mutations in certain genes that regulate circadian rhythms, suggesting adaptation to the extreme light cycles of northern summers and winters.
- [8]
M. trumani has often been cited as the evolutionary reason the American pronghorn is so fast; the 'ghosts of predators past' hypothesis holds that the pronghorn's extreme speed was a coevolved defense against high-speed pursuit by a cheetah-like hunter.
- [9]
American pronghorn can sprint up to nearly 90 kilometers per hour.
- [10]
The slender, cheetah-like body of M. trumani is now understood as a striking example of evolutionary convergence.
- [11]
This and other recent research suggest M. trumani was a versatile predator capable of both terrestrial pursuit and grasping prey with powerful forelimbs.
- [12]
Co-author Matthew Wooller, a professor in the College of Fisheries and Ocean Sciences at the University of Alaska Fairbanks, said the carnivore had a massive range from the Arctic to the Lower 48 and demonstrated uber-specialization at two ends of that range while feeding on two completely different food sources.
- [13]
The team used a heavy form of nitrogen to place M. trumani in the food chain: predators that eat other animals carry more heavy nitrogen relative to the lighter form. Wyoming specimens indicated a terrestrial carnivore eating herbivores; Yukon specimens had heavy nitrogen levels comparable to marine carnivores such as orcas, suggesting a nearly exclusive fish diet.
- [14]
The original goal was to use ancient genetic material to verify the identity of three roughly 31,000-year-old Yukon fossils that had been tentatively identified as pumas because they were found so far north; Cassatt-Johnstone said it was not until the genetic data were generated that they were identified as American cheetahs, which led to a discovery avalanche.
- [15]
The team sequenced high-coverage genomes from fossils dating back 23,000 to 31,000 years.
- [16]
M. trumani and all felid lineages sampled in the study lacked a functional gene encoding a receptor for sour taste, the first recorded instance in felids of inactivation of genes involved in perceiving sour flavors, a trait sometimes associated with highly specialized diets.
- [17]
M. trumani in Wyoming and the Yukon had low genetic diversity but showed no signs of inbreeding or sharp bottlenecks, only a slow long-term decline from the early to the late Pleistocene, which may explain their scarcity in the fossil record.
- [18]
Senior author Beth Shapiro said low genetic diversity did not doom this species by itself.
- [19]
Fossil specimens analyzed from Yukon Territory were recovered from the Tr'ondek Hwech'in and Vuntut Gwitchin Traditional Territories, with respect for their stewardship of these lands.
- [20]
Cassatt-Johnstone, a molecular ecologist at UC Santa Cruz, said calling it the American cheetah implies a specific behavior and ecology that is not necessarily appropriate for this species.
- [21]
It is unknown whether northern M. trumani caught fish themselves or scavenged carcasses along riverbanks.
- [22]
About 2.1 million years separate M. trumani's split from cheetahs and its split from pumas.
- [23]
Four M. trumani individuals yielded the ancient DNA behind the reclassification.
- [24]
Larisa DeSantis, a paleoecologist at Vanderbilt University who was not involved with the work, said that if the cats could exploit an abundant prey resource that did not cause significant injury, that is a win-win.
- [25]
Scrutinizing more specimens across the species' range, including south of Wyoming, could reveal how adaptable the 'American cheetah' truly was and how much the nickname has obscured.
- [26]
One of the Yukon fossils was found in a cave that also harbors many Pleistocene fish fossils, which Cassatt-Johnstone said shows the resource was around and could have been exploited.
Sources
3 independent publishers whose own reporting we read for this story.
- discovermagazine.com30,000-Year-Old Fossils Reveal the “American Cheetah” Was Actually More Like a Puma
1 article · September 4, 2026
- phys.orgNot a cheetah: Ancient DNA reveals the surprising Arctic life of extinct North American cat
2 articles · September 6, 2026
- sciencedaily.comThe American “cheetah” wasn’t a cheetah at all
1 article · September 8, 2026
- sciencenews.orgWas the ‘American cheetah’ a cheetah at all?
1 article · September 4, 2026
Topics and entities
Topics
- Species Classification
- Stable Isotope Ecology
- Convergent Evolution
- Pleistocene Megafauna
Entities
- Miracinonyx trumani
- American Pronghorn
- Vanderbilt University
- University of California, Santa Cruz
- Current Biology
- Molly Cassatt-Johnstone
- Natural Trap Cave
- University of Alaska Fairbanks