| Metailurini, Metailurus, Paramachairodus, Carnivores, Nimravides|
Adelphailurus is an extinct genus of saber-toothed cats of the family Felidae and tribe Metailurini which inhabited western North America during the Miocene, living from 10.3—5.33 Ma and existing for approximately 4.97 million years.
Adelphailurus was named by Hibbard (1934). Its type is Adelphailurus kansensis. It was assigned to Felidae by Hibbard (1934) and Carroll (1988); and to Machairodontinae by Martin (1998).
It was a cougar-sized animal and may have had habits similar to those of a cougar. Its body had the same shape as a cougar except for a long and compressed upper canine. This would place this cat into the "false-sabertooth" group. Apart from that the Adelphailurus had a retained upper second premolar, which is unusual for a cat.
Two specimens were examined by Legendre and Roth for body mass.9.56 kg (21 lb)
26.7 kg (59 lb)