In the Bluefish Caves and a mining location in northern Yukon, bones initially believed to be from an ice-age puma or cougar were proven otherwise through DNA testing conducted by the University of California. The analysis, carried out by Molly Cassatt-Johnstone, a recent graduate and lab technician at the time, revealed surprising results. The bones, which were among Cassatt-Johnstone’s first samples to work on, turned out to be from Miracinonyx, also known as the extinct American cheetah.
Grant Zazula, a paleontologist in Yukon, vividly recalls his astonishment upon receiving the news that the creatures were not cougars but cheetahs. The discovery marked a significant advancement in ancient DNA analysis, which was once considered futuristic but is now a routine practice for studying permafrost-preserved bones.
Cassatt-Johnstone’s identification of the Yukon Miracinonyx led to her being the lead author of a paper published in Current Biology, shedding new light on the ice-age cat’s diet and habitat. Researchers were puzzled by the presence of American cheetahs in the Arctic tundra, a stark contrast to their presumed habitat of chasing pronghorns across grassy plains.
By utilizing stable isotope analysis, researchers delved into the dietary habits of the Yukon cheetahs. Surprisingly, the study revealed that these felines predominantly fed on fish, a behavior uncommon among both historical and contemporary cats. The findings suggest that the abundance of Yukon salmon might have facilitated the survival of these cheetahs in a region where they coexisted with formidable predators like Beringian lions and giant bears.
Further genetic analysis indicated that Miracinonyx was more closely related to North American pumas than African cheetahs. The study also highlighted the low genetic diversity and limited adaptive potential of the cheetah population, potentially contributing to their extinction. Zazula proposed renaming this distinctive northern population from ‘American Cheetah’ to ‘Yukon Cheetah’ to reflect their unique ecological niche.
The discovery underscores the significance of ongoing paleontological research in uncovering new insights into ancient ecosystems and species dynamics.
