Bones discovered in the Bluefish Caves and a mine site in northern Yukon were initially believed to belong to an ice-age puma or cougar. However, DNA analysis conducted by the University of California revealed a surprising twist. The testing was carried out by Molly Cassatt-Johnstone, a lab technician who had recently completed her undergraduate studies. She vividly recalls her astonishment when the preliminary results indicated that the bones were not from pumas but rather cheetahs.
Yukon paleontologist Grant Zazula vividly remembers the moment he received the unexpected news that the animals were cheetahs, not cougars. The discovery marked a significant advancement in ancient DNA analysis, which was once considered akin to science fiction but has now become a standard practice in studying permafrost-preserved bones from the Yukon.
Cassatt-Johnstone’s groundbreaking identification of a Yukon Miracinonyx, the extinct American cheetah, led to her becoming the lead author of a paper published in Current Biology. The study sheds new light on the ice-age cat’s dietary habits and geographical range.
Researchers had long thought that the American cheetah, resembling modern cheetahs with their long limbs and slender physique, would have evolved to hunt pronghorns across grassy plains. The discovery of these creatures in the Arctic tundra puzzled paleontologists as there were no pronghorn antelope in Beringia, the region connecting Asia and North America, including parts of Russia, Alaska, and the Yukon.
To unravel the mystery of how Miracinonyx thrived in this region, researchers, in collaboration with Canadian and U.S. counterparts, utilized stable isotope analysis. This technique, commonly used in forensics, provides insights into the diet, climate, and migration patterns of ancient beings. Analysis of bone fragments from the cheetah’s limbs revealed a surprising diet consisting mainly of fish, a behavior uncommon among both past and present-day felines.
The revelation that Yukon cheetahs primarily fed on salmon astonished paleontologists like Julie Meachen, who specializes in studying mammalian carnivores from the Late Pleistocene. The study also revealed that Miracinonyx was genetically closer to North American pumas than African cheetahs, with low genetic diversity potentially contributing to their extinction.
Grant Zazula proposed renaming this unique northern population from ‘American Cheetah’ to ‘Yukon Cheetah,’ highlighting the significance of each new bone discovery in unraveling the mysteries of the past. The study underscores the importance of continuous exploration and research in paleontology to unveil untold stories hidden within ancient bones.