American 'Cheetah' Was a Puma Relative, DNA Reveals
Extinct big cat's diet and range rewrite its evolutionary story
1Misidentified Predator
Miracinonyx trumani, nicknamed the American cheetah due to its speed-adapted physique, was actually a puma relative according to new DNA analysis. The Pleistocene-era cat's elongated legs and large sinuses initially suggested cheetah-like traits. However, 2005 mitochondrial DNA from Wyoming fossils first hinted at its puma lineage, now confirmed by UC Santa Cruz researchers in Current Biology.
2Convergent Evolution Trick
The species' cheetah-like features—including slender bodies and long limbs—represent a striking case of convergent evolution, where unrelated species develop similar traits. First described in 1979, M. trumani's morphology misled scientists for decades. Lead author Molly Cassatt-Johnstone notes this parallels Australia's extinct thylacine, which resembled wolves despite being a marsupial.
3Arctic Fish Specialist
Surprisingly, northern populations in Yukon's Beringia region specialized in salmon fishing rather than speed-based hunting. This marks the first evidence of M. trumani's Arctic presence. Their fish-heavy diet contrasts sharply with southern relatives in Wyoming and Florida, who hunted grassland prey. The discovery expands the species' known range by 1,500 miles northward.
4Dietary Adaptations
While southern M. trumani were generalist predators in temperate grasslands, Arctic populations developed niche survival strategies. Isotopic analysis of fossils reveals Yukon cats relied 80% on aquatic food sources—a flexibility mirroring modern brown bears. This dietary split suggests the species adapted rapidly to diverse Ice Age ecosystems across North America.
5Evolutionary Context
The findings clarify M. trumani's place in the felid family tree. True cheetahs (Acinonyx) diverged from puma lineages 6.7 million years ago, while M. trumani shares a last common ancestor with pumas just 4.2 million years back. This explains genetic similarities despite superficial cheetah-like traits—a case of form following function rather than ancestry.
6Pleistocene Ecosystem Puzzle
Adding M. trumani to Beringia's predator roster changes understanding of Ice Age food webs. Previously thought to lack mid-sized carnivores, the region now shows three-tiered predation: fish-eating M. trumani, wolf-like canids, and saber-toothed cats. The study used collagen protein analysis from 30,000-year-old fossils to reconstruct these relationships.
7Naming Controversy
The 'American cheetah' label persists despite being scientifically inaccurate. Gizmodo reports some paleontologists advocate renaming it 'North American puma' to reflect genetic ties. However, Phys.org notes the nickname endures due to public familiarity and the species' ecological role as a speed-adapted predator—even if not a true cheetah.
8Research Implications
This study highlights how DNA and isotopic tools reshape paleontology. By combining genetics with dietary analysis, researchers revealed a species more adaptable and widespread than fossils alone suggested. Future work may explore why M. trumani vanished 12,000 years ago while pumas survived—a mystery potentially tied to specialized Arctic populations' vulnerability during climate shifts.
Original article: Gizmodo — American 'Cheetah' Was a Puma Relative, DNA Reveals