Ancient DNA and isotopic analysis show that the extinct North American Ice Age predator known as the “American cheetah” was not a cheetah at all, but rather a close sister species to the modern puma (Puma concolor), according to a study published in the journal Current Biology. Researchers discovered that Miracinonyx trumani exhibited extreme ecological flexibility, with northern populations in the Canadian Arctic adopting a pescatarian diet and specific genetic adaptations to survive extreme light cycles, while southern counterparts hunted land prey.
Genomic Analysis Overturns the American Cheetah Classification
For decades, paleontologists categorized Miracinonyx trumani as an endemic American counterpart to the African cheetah (Acinonyx jubatus) due to shared physical traits. According to paleogenomicist Molly Cassatt-Johnstone at the University of California, Santa Cruz (UCSC), those cursorial adaptations—including slender builds, long limbs, and increased nasal turbinate capacities functioning like turbochargers to boost oxygen intake—evolved independently through convergent evolution.
By analyzing DNA from four fossil specimens, including a roughly 23,000-year-old specimen from Natural Trap Cave in Wyoming and three specimens from the Canadian Yukon dating back more than 30,000 years, researchers determined that the lineage split from modern pumas approximately 2.6 million years ago. “It’s very hard to imagine a prehistoric species we’ve never seen without comparing it to something we know,” Cassatt-Johnstone states regarding the historical misclassification.
Dietary Specialization and Arctic Adaptations in the Yukon
The inclusion of Yukon specimens in the genomic evaluation extended the known geographic range of M. trumani northward by 20 degrees of latitude, or more than 1,400 miles. According to paleoecologist Matthew Wooler, director of the Alaska Stable Isotope Facility at the University of Alaska Fairbanks (UAF), the carnivore demonstrated über-specialization across different ends of its range.
Nitrogen isotope analysis revealed that the northern population developed a pescatarian diet. These cats consumed fish such as salmon, leaving chemical signatures similar to those found in modern orcas and sea wolves. Furthermore, genetic sequencing identified loss-of-function mutations in genes regulating circadian rhythms. According to Cassatt-Johnstone, these mutations suggest the cats adapted biologically to the extreme seasonal light cycles of Arctic winters and summers.
Did you know? While Miracinonyx trumani shared physical speed adaptations with the African cheetah, its lineage diverged from the modern puma around 2.6 million years ago, proving that its cat-like agility was the result of convergent evolution rather than direct ancestry.
Pleistocene Extinction and the End of the Ice Age
During the Pleistocene epoch, which lasted from roughly 2.58 million to 11,700 years ago, M. trumani inhabited a crowded carnivore guild alongside cave lions, scimitar-toothed cats, gray wolves, and brown bears. According to UCSC ecologist and evolutionary biologist Beth Shapiro, the species persisted for an extended period without showing typical signs of genetic inbreeding prior to a population collapse.
The decline of M. trumani unfolded slowly as the Pleistocene progressed and the last glacial period gave way to a warmer climate. Shapiro notes that this prolonged decline ultimately left the adaptable predator unequipped to survive the profound environmental shifts that closed the curtain on iconic Ice Age fauna like the woolly mammoth.
Frequently Asked Questions
What was the “American cheetah” actually related to?
According to research published in Current Biology, ancient DNA proves that Miracinonyx trumani was a sister species to the modern puma (Puma concolor) rather than a close relative of the African cheetah.
How far north did Miracinonyx trumani range?
Genetic confirmation of Yukon specimens extended the known range of M. trumani by 20 degrees of latitude, showing it lived all the way from the Arctic down to the Lower 48 states.
What did northern populations of this cat eat?
Isotopic analysis indicates that northern populations in the Yukon were pescatarian, relying heavily on fish such as salmon alongside their southern relatives who hunted land prey.
Want to stay updated on the latest archaeological and paleontological discoveries? Explore our related coverage on prehistoric ecosystems, or subscribe to our newsletter for weekly updates straight to your inbox.
Worth a look