For several decades, paleontologists have described Miracinonyx trumani — an extinct species of cheetah-like felid that roamed the North American prairies and steppe terrains more than 13,000 years ago — as North America’s answer to the African cheetah (Acinonyx jubatus). New research led by the University of California, Santa Cruz suggests the picture was largely wrong.
Miracinonyx trumani and the ecosystem this species lived in. Image credit: Julius Csotonyi.
Miracinonyx trumani roamed North America’s open grasslands during the Pleistocene epoch, about 2.5 million to 13,000 years ago.
Based on fossils uncovered to date, the species was 90 cm (3 feet) tall, about 2.5 m (8 feet) long to the tip of its tail, and weighed around 70 kg (150 pounds) on average.
It had a slender body shape, long forelimbs, and large nasal cavities — features that are characteristic of modern fast-running animals such as cheetahs or horses.
Some Miracinonyx trumani fossils have been unearthed alongside those of pronghorns, fast-running animals known colloquially as the ‘American antelope,’ leading researchers to assume that the extinct felid had a similar lifestyle to modern African cheetahs.
“These cats were remarkably flexible, much like pumas are across their range today,” said Molly Cassatt-Johnstone, a Ph.D. candidate at the University of California, Santa Cruz.
“We found loss-of-function mutations in certain genes that regulate circadian rhythms, suggesting they may have adapted to the extreme light cycles of summers and winters in northern latitudes.”
Cassatt-Johnstone and her colleagues used ancient DNA extracted from four Miracinonyx trumani specimens — one from Natural Trap Cave in Wyoming and three from Yukon Territory — to sequence the first high-coverage nuclear genomes of the ancient species.
“It’s very hard to imagine a prehistoric species we’ve never seen without comparing it to something we know,” Cassatt-Johnstone said.
“But this approach can limit our understanding of ancient animals’ complexity, unique evolutionary histories, and behaviors.”
The genetic analysis places the felid as the closest relative of the living puma (Puma concolor), not the cheetah, confirming and extending earlier findings based on more limited mitochondrial DNA.
The two lineages are estimated to have split around 2.6 million years ago, while Miracinonyx trumani’s sleek, cheetah-like build appears to be a case of convergent evolution: similar body shapes arising independently in response to similar open-habitat hunting pressures, rather than shared ancestry with African cheetahs.
The Yukon fossils also push the species’ known range dramatically northward — by more than 20 degrees of latitude — showing that the felid lived in Arctic steppe-tundra environments roughly 31,000 to 34,000 years ago, far beyond the temperate grasslands where most previous fossils had been found.
Two of the Yukon specimens had originally been misidentified as pumas because of their location so far outside Miracinonyx trumani’s expected range.
