A 2026 study using ancient DNA and isotopic analysis revealed that the Ice Age American cheetah (Miracinonyx trumani) was not a true cheetah but a puma relative with a surprising Arctic diet, challenging long-held assumptions about its ecology and evolution.
The Ice Age American cheetah was not a cheetah at all. A study published in the journal Current Biology reclassified Miracinonyx trumani as a close relative of modern pumas, based on genetic analysis of fossils from Wyoming and the Yukon. This discovery upends a decades-old narrative that depicted the species as a sprinting predator chasing pronghorns across North American grasslands.
Researchers led by Molly Cassatt-Johnstone of the University of California, Santa Cruz (UCSC), sequenced ancient DNA from four Miracinonyx trumani fossils, including specimens from Natural Trap Cave, Wyoming, and the Yukon. The genetic data placed the species closer to pumas (Puma concolor) than to African cheetahs (Acinonyx jubatus), with both lineages diverging around 2.6 million years ago. This challenges the earlier assumption that Miracinonyx was a North American cheetah equivalent.
The 'American Cheetah' Was Actually a Different Animal All
It's very hard to imagine a prehistoric species we've never seen without comparing it to something we know,
Cassatt-Johnstone said in a press release. But this approach can limit our understanding of ancient animals' complexity…
The study’s findings were corroborated by isotopic analysis of fossils, which revealed dietary differences between northern and southern populations.
The research extended Miracinonyx’s known range by 20 degrees of latitude, from Florida to the Arctic Yukon. Fossils from the Yukon, dating to 31,000–34,000 years ago, showed the species adapted to extreme northern environments. Isotopic analysis of nitrogen and carbon in their bones indicated a diet rich in fish, likely salmon, contrasting with the southern Wyoming fossils, which suggested a land-based diet of herbivores like pronghorns, horses, bison, and bighorn sheep.
The dietary shift may have helped Miracinonyx avoid competition with larger predators like cave lions and scimitar-toothed cats.
American cheetah was not actually a cheetah, DNA reveals
Genetic analysis uncovered loss-of-function mutations in genes regulating circadian rhythms, suggesting Miracinonyx adapted to the extreme light cycles of Arctic summers and winters. These mutations may have allowed the cats to remain active during prolonged daylight or darkness, a critical survival trait in northern latitudes.
We found loss-of-function mutations in certain genes that regulate circadian rhythms,
Cassatt-Johnstone explained. Suggesting they may have adapted to the extreme light cycles of summers and winters in northern latitudes.
This genetic flexibility highlights the species’ ability to thrive in diverse environments, from temperate grasslands to Arctic tundra.
The study also revealed convergent evolution: Miracinonyx and modern pumas developed similar cursorial traits independently, driven by the need for speed in open landscapes. These cats were remarkably flexible, much like pumas are across their range today,
Cassatt-Johnstone said.
Despite these adaptations, Miracinonyx disappeared with the end of the last ice age. Its legacy, however, endures in the scientific community. There are probably other extinct species that, unfortunately, have been reduced to fewer dimensions than they deserve,
Cassatt-Johnstone noted. The findings underscore the importance of genetic and isotopic analysis in redefining prehistoric ecosystems.
DNA Reveals the Extinct ‘American Cheetah’ Wasn’t Actually a
The research, supported by multiple institutions including UCSC, UAF, and Des Moines University, offers a new framework for understanding Ice Age megafauna. As scientists continue to analyze ancient DNA, the story of the American cheetah serves as a reminder that nature’s complexity often defies simple classifications.
Julie Meachen, a National Geographic Explorer and functional morphologist at Des Moines University, led the 2014 expedition that found specimens in Wyoming’s Natural Trap Cave. She emphasized the study’s significance, stating, This study is the first published record of Miracinonyx in Canada.
The Yukon fossils, previously mistaken for another kind of cat, were identified as Miracinonyx trumani through DNA analysis, extending its known range into the Arctic.
Stephen O’Brien, a molecular biologist not involved in the study, noted that genetic evidence from fossils frequently revises evolutionary conclusions. We are regularly correcting evolutionary conclusions that were based on anatomical interpretations,
he said. The team’s work, which included examining DNA from the cell nucleus, built on earlier mitochondrial DNA studies that hinted at Miracinonyx’s puma-like lineage.
The study analyzed DNA from a Wyoming fossil and three Yukon fossils, including specimens from Bluefish Caves. These findings, published in Current Biology, highlight the species’ adaptability and the value of interdisciplinary approaches in paleontology. Miracinonyx trumani, once thought to be a cheetah, now stands as a testament to the dynamic interplay between genetics, environment, and evolution.
