Acinonyx

Acinonyx is a genus of cats, family Felidae, subfamily Felinae, containing one living species, the cheetah, Acinonyx jubatus, plus five extinct species described from the fossil record. The genus is a highly adapted lineage specialized for speed and open-terrain hunting: its claws cannot be fully retracted, giving extra traction while running, and the modern cheetah has a notably slimmer build for quick pursuit than its ancestral relatives. The cheetah now occupies open grasslands of Africa and a small remnant population in Iran; a critically endangered Asiatic subspecies separated from African populations an estimated 32,000 to 67,000 years ago, and most other species in the genus went extinct during the Pleistocene from climate change, habitat loss and prey depletion.