Acinonyx is a genus that is within the Felidae family, also known as the cat family. The only living species of the genus and most commonly known, the cheetah (A. jubatus) inhabits the open grasslands of Africa and Asia in parts of Iran. This genus represents a highly adapted lineage within the felids, which specialize in speed and open-terrain hunting. Evidence suggest the Acinonyx genus evolved from other feline ancestors early on, to become specialized in stealth and running.
The main reasons for all but one species going extinct revolve around climate changes, humans driving these species out of their habitats, and their prey populations shrinking. Climate drastically changed starting in the Pleistocene period, making it difficult to survive in open terrain and grasslands upon which these cats depend. Human civilization also began to change and expand resulting in lots of these species to lose their home or hunting grounds. This also forced some species to be isolated making reproducing more difficult. indicating a wide time range. These cats occurred across much of the old world 10,000 years ago, some extinct species such as A. pardinensis and A. intermedius were found in parts of Europe and Asia.
Taxonomy
Acinonyx was proposed by Joshua Brookes in 1828.
The word Acinonyx is greek, the first portion of "akinetos" translates to "unmoved" or "motionless" and the second portion "onyx" translates to "nail" or "claw". Which represents one the main traits used to recognize this genus, not being able to retract their claws fully.
- Felis venatica by Griffith in 1821 was based on a sketch of a cheetah from India.
- Cynailurus soemmeringi by Fitzinger in 1855 was a live male cheetah brought by Theodor von Heuglin to Tiergarten Schönbrunn from Kordofan in southern Sudan.
- Acinonyx hecki by Hilzheimer in 1913 was a captive cheetah from Senegal in the Berlin Zoological Garden, named in honour of the zoo's director.
In 1993, Acinonyx was placed in the monophyletic subfamily Acinonychinae. Molecular phylogenetic analysis has shown that it is the sister group of the genus Puma, and it is now placed within the subfamily Felinae.
- Acinonyx arvernensis by Croizet et Jobert in 1828
- Acinonyx aicha by Geraads in 1997
- Acinonyx pleistocaenicus by Zdansky in 1925
The Asiatic cheetah ("Acinonyx jubatus venaticus") is part of the last surviving lineages that are outside of Africa. Recent genetic studies have shown that this subspecies separated from African populations roughly 32,000 to 67,000 years ago, suggesting a prolonged adaptation to dry landscapes. In 2012, "A. kurteni" was invalidated as a species when the holotype was determined to be a forgery composed of Miocene-aged fragments.
The extended duration and broad range of fossil records suggests the long evolutionary presence across the old world into the present day. The fossils also suggest how the genus Acinonyx once ranged widely across Eurasia, eventually population declining to climatic shifts and the habitat being broken into different locations due to human activities.