Ancient DNA and fossil analysis reveal that the extinct North American feline known as the American cheetah was actually a sister species to the modern puma. Researchers discovered the animal ranged into the Arctic Yukon and adapted its diet to include fish, shifting long-held paleontological assumptions about its Ice Age behavior.
Genetic Evidence Links the Extinct Cat to Modern Pumas
For generations, paleontologists pictured Miracinonyx trumani as a high-speed sprinter chasing pronghorn across Pleistocene grasslands. Its long limbs, slender build, and enlarged nasal cavities suggested an evolutionary path similar to the African cheetah. But a comprehensive genomic analysis published in Current Biology tells a different story.
When researchers constructed a feline family tree using DNA extracted from the cell nucleus of fossils, the four American cheetahs grouped closely with the American puma rather than African or Asiatic cheetahs. The two lineages diverged approximately 2.6 million years ago during a period of rapid continental cooling and expanding grasslands, according to scientific findings.
“It’s very hard to imagine a prehistoric species we’ve never seen without comparing it to something we know. But this approach can limit our understanding of ancient animals’ complexity, unique evolutionary histories, and behaviors.”
Molly Cassatt-Johnstone, paleogenomicist at the University of California, Santa Cruz
As described in the new paper, published in the journal Current Biology, Miracinonyx trumani was thought to be an endemic American version of the African cheetah. Earlier DNA from mitochondria had already suggested that the cat might be closer to pumas, but the new work went further by examining DNA from the cell nucleus, which contains much more genetic information. The team produced high-quality ancient genomes from a fossil in Natural Trap Cave, Wyoming, and another from Bluefish Caves in Yukon.
The major conclusion that Miracinonyx and pumas were sister species seems plausible,
says Stephen O’Brien, a molecular biologist who produced an earlier construction of the felid family tree but was not involved in the recent work. He adds that it is common for genetic evidence from fossils to result in such revisions, noting that researchers are regularly correcting evolutionary conclusions that were based on anatomical interpretations.
Arctic Fossils Reveal a Broader Range and Flexible Diet
The study also pushed the known northern boundary of Miracinonyx trumani more than 20 degrees of latitude farther north. Researchers examined three roughly 30,000-year-old fossils from the Arctic Yukon that had previously been mistaken for another kind of cat. DNA showed that all three were actually Miracinonyx trumani, extending its known range into the Arctic and marking the first published record of Miracinonyx in Canada.
National Geographic Explorer Julie Meachen, a functional morphologist and paleoecologist at Des Moines University in Iowa and a coauthor of the study, led the 2014 expedition that found several specimens in Wyoming’s Natural Trap Cave. She points out that the findings show this extinct species could survive in various habitats and was eating very different things in different places.
Convergent Evolution and Re-evaluating the Past
The cheetah-like body evolved on its own through a process called convergent evolution, which happens when unrelated animals develop similar features under similar environmental pressures. An adult M. trumani stretched roughly 8 feet from nose to tail, stood about 3 feet tall, and weighed an estimated 150 pounds. Its enlarged nasal cavities may have helped it move more air while running, which was another reason paleontologists pictured it as a high-speed hunter.
Before that identification, paleontologists knew M. trumani from sites farther south, including Wyoming. At some of those sites, its fossils appeared alongside pronghorn remains, helping inspire the thought that it was a sprinter chasing its prey across open landscapes. The new findings demonstrate that fossils do not always tell the full story of an animal, and that ancient DNA and chemical clues from bones reveal an animal that could live in different environments and eat different kinds of food.
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