Ancient DNA Proves the Extinct ‘American Cheetah’ Split from Pumas 2.6 Million Years Ago

**New Insights into the Extinct American Cheetah: A Study from Canada’s Yukon**

Recent research has shed light on the fascinating history of the extinct species commonly known as the “American cheetah.” Fossils unearthed in the Yukon region of Canada represent the first recorded evidence of this ancient feline in the Pleistocene ecosystem of Beringia, the land bridge that once connected Siberia to Alaska. The study, conducted by a team from the University of California, Santa Cruz, has offered a fresh perspective on the evolutionary lineage and ecological role of this long-extinct carnivore.

The term “American cheetah” might suggest specific behaviours and ecological adaptations. However, lead researcher Molly Cassatt-Johnstone, a molecular ecologist, emphasised that such a label does not accurately reflect the species’ characteristics. The research team sequenced ancient DNA from four Miracinonyx trumani fossils, revealing that the American cheetah was more closely related to modern pumas than to its African counterpart. This surprising finding challenges long-held assumptions regarding its classification and ecological niche.

The fossils analysed in this study were primarily sourced from the Yukon: three originated from the Bluefish Caves near Old Crow, while the fourth was found in thawed permafrost at a Quartz Creek gold mine within the Klondike. The ages of these specimens range from approximately 31,000 to 34,000 years ago, with the Wyoming ear bone dating back approximately 23,500 years. Cassatt-Johnstone remarked on the excitement of adding a new carnivore to the ancient Beringian ecosystem, highlighting the significance of these discoveries.

Historically, scientists believed that American cheetahs occupied open plains and hunted prey such as pronghorn. However, the team’s analysis revealed that pronghorn were not native to northern regions like the Yukon during that period. To better understand the diet of these ancient predators, researchers measured the nitrogen levels in their bone chemistry, resulting in intriguing conclusions. The nitrogen levels were notably elevated compared to other carnivores from the same epoch, suggesting a unique dietary preference.

Interestingly, the team’s findings indicate that the American cheetah may have had a fish-heavy diet, similar to that of modern-day Alaska brown bears, who consume a significant proportion of salmon. The nitrogen isotope ratios in the bones suggest that these ancient felines were likely adept at catching fish, although further research is needed to determine the methods this species employed to capture such prey.

The study highlights the complexity and adaptability of Miracinonyx trumani, far beyond what its common name implies. The misconception that these cats were simply scaled-down versions of African cheetahs fails to capture their independent evolutionary journey. While their physical characteristics resemble those of their African relatives—including long legs and slender bodies—the research indicates that such traits evolved independently over millions of years.

Cassatt-Johnstone pointed out that it is crucial to reassess the labels assigned to extinct species, as they can sometimes limit our understanding of their ecological roles. “There are probably other extinct species that have been reduced to fewer dimensions than they deserve,” she said, underscoring the need for continual examination of ancient lineages.

Through advanced molecular analysis and fossil examination, this study not only adds to the understanding of the American cheetah’s evolutionary history but also contributes to our broader knowledge of Pleistocene ecosystems. As researchers uncover more discoveries from the past, the insights gained will continue to reshape the narratives surrounding the lives and behaviours of extinct species.

The findings of this groundbreaking study were published in *Current Biology* in early September, providing a new framework for understanding the complexities of this unusual extinct cat. The study serves as a reminder of the richness of Earth’s evolutionary history and the importance of maintaining a nuanced perspective on the creatures that once roamed the land.