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Extinct American Cheetahs (Miracinonyx spp.) Fact Sheet: Taxonomy & History

How Do We Know This?

Like living animals, fossil remains of once-living animals are classified and grouped according to their relationships to each other and to their ancestors.

Taxonomic History & Nomenclature

Taxonomy of the American cheetah has been difficult

  • Previously assigned to the genera Felis, Puma and Acinonyx (Van Valkenburgh et al 1990)
  • Now thought distinct enough to be in its own genus, Miracinonyx. (Van Valkenburgh et al 1990)
  • American cheetahs and African cheetahs have only a small number of shared traits, thus should not be in the same genera. (Van Valkenburgh et al 1990)
  • A third native American cat, the jaguarundi, groups with Miracinonyx and the puma according to DNA studies. (Barnett et al 2005)

Cheetahs and pumas share many traits and have a close relationship, according to modern DNA studies (Barnett et al 2005)

Scientific name: Miracinonyx inexpectatus.

  • Mira from Latin for "wonderful"
  • acinonyx from Gk. akineo (no movement) + onyx (claw), referring to false belief that cheetahs have non-retractable claws
  • inexpectatus from Latin for "unexpected"
  • thus, "wonderful unexpected cheetah"

Common name

  • American cheetah

Evolutionary History

Cats of the cheetah-puma group diverged between 7.2 million years ago (Miocene) from the cat family, Felidae. (Johnson et al 2006)

Much discussion in literature about Old World vs New World origins for cheetahs and the relationship between modern cheetahs (Acinonyx) and the extinct American cheetah (Miracinonyx) (Christiansen & Mazak 2009)

  • An extensive molecular phylogeny of the cat family suggests the American cheetah originated in the North American puma lineage and later migrated to central Asia and Africa. (Johnson et al 2006)
  • Other studies of actual fossils suggest that American cheetah ancestors came from Europe/Asia and migrated to North America (Kurtén 1976) (Christiansen & Mazak 2009)
    • Not likely that American cheetah came from an endemic North American ancestor shared with pumas since oldest NA pumas date to only 400,000 years ago; older more primitive pumas lived in Europe and Asia
    • Puma-Miracinonyx-Acinonyx group may be of Eurasian-African origin, perhaps migrating more than once to North America. (Van Valkenburgh et al 1990)

Miracinonxy and Acinonyx had separate evolutionary histories for about the last 4 million years (Van Valkenburgh et al 1990)

Miracinonyx inexpectatus first appears between 3.2 and 2.5 million years ago (Pliocene) in Texas. (Van Valkenburgh et al 1990)

In equally old sediments, fossils of a true cheetah found recently in China (Christiansen 2009)

  • Acinonyx kurten (2.55-2.16 million years ago (Pliocene)
  • Has both puma-like and cheetah-like features..

M. trumani occurs in younger sediments (Pleistocene) and doesn't overlap in time with M. inexpectatus

  • Looks more like modern cheetahs in its skull and tooth morphology (Christiansen & Mazak 2009)

Miracinonyx became extinct with other Pleistocene megafauna around 12,000 years ago.

Modern cheetahs display a significant reduction (90-99%) in genetic variation compared to other felid species (Menotti-Raymond & O'Brien 1993)

  • Reduction seems to be the result of near-extinction 10,000 years ago (the end of the Pleistocene).

Cheetahs, although present almost entirely in African grasslands and semi-deserts, until exterminated by humans existed also in Asia .

Classification

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Suborder: Feliformia

Family: Felidae

Genus: Miracinonyx - extinct

Species: Miracinonyx inexpectatus (Cope 1895) - American cheetah (extinct)
Species: Miracinonyx trumani - extinct

Page Citations

Barnett et al (2005)
Christiansen & Mazak (2009)
Menotti-Raymond & O'Brien (1993)
Valkenburgh et al (1990)
Johnson et al (2006)

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