In 1884, Lydekker described two rami from the Pinjor Formation as Felis (?Cynaelurus) brachygnatha.[1] Later, in 1925, Zdansky described Cynailurus pleistocaenicus based on fossils from Shansi, China.[2]
In 1929, Hungarian palaeontologist Miklos Kretzoi described several new genera and species: in one paper he re-assigned Felis (Cynaelurus) brachygnatha as Acinonyx brachygnathus, re-described one of its two referred specimens as the new genus and species Sivapanthera lydekkeri;[3] then in a second paper, he described the genus Abacinonyx for Cynailurus pleistocaenicus (the type species) and Felis (Cynaelurus) brachygnathus.[4]
Also in 1929, American paleontologist W. D. Matthews made a review of Siwalik mammals in which he considered Cynailurus pleistoceanicus a junior synonym of Felis brachygnatha, which was also very similar to Felis arvernensis.[5]
Guy Ellcock Pilgrim, in 1932, described a new genus Sivafelis, with the new species Sivafelis potens as the type species and including Felis (?Cynaelurus) brachygnatha (=Sivafelis brachygnathus, and including Sivapanthera lydekkeri as a synonym) and Cynailurus pleistocaenicus (=Sivafelis pleistocaenicus). He admitted that both Abacinonyx and Sivapanthera were older, but stated that the confusion around the type species- Sivapanthera was the senior-most name but its type species was a junior synonym of Abacinonyx' type- compelled him to name a new genus.[6] Colbert Edwin, in his review of Siwalik mammals, followed Pilgrim's assignment of Sivafelis brachygnathus and Sivafelis potens.[7] But Simpson in 1945 noted that Sivapanthera was the senior and thus correct name for the genus, rendering Sivafelis and Abacinonyx junior synonyms.[8]
A fourth species, Sivapanthera linxiaensis from Early Pleistocene deposits in China's Dongxiang Autonomous County, was described in 2004.[9]
The status of Sivapanthera species is unresolved, with some researchers considering them all junior synonyms of Acinonyx pardinensis, subspecies of A. pardinensis, species in the genus Acinonyx, or belonging to the genus Sivapanthera is various states of synonymy with each other.[10][11] One paper has suggested in passing that S. potens is a synonym of S. brachygnathus,[12] while another paper stated that "S." potens was unlikely to belong to the same genus and was, in fact, more similar to Panthera uncia and Panthera onca.[13] In 2024, S. pleistocaenicus was reclassified as a new species of Acinonyx.[14]
