Proailurus was a prehistoric carnivore that lived in Europe and Asia approximately 25 million years ago in the late Oligocene and Late Miocene. A recent phylogeny[1] places it as a basal feloid, the superfamily that includes mongooses, civets, hyenas, and cats; however, some sources show it as a felid and a direct ancestor of cats.[2] Proailurus was a compact and small animal, just a little larger than the domestic cat, weighing about a slender 20 lb (9 kg). It had a long tail, large eyes and sharp claws and teeth, with similar proportions to the modern viverrids. Like the vivverids, it was probably a tree-dweller.[3]. Proailurus may be ancestral to Pseudaelurus, which lived 20-10 million years ago and probably gave rise to the major felid lines, including the machairodontines, felines and pantherines.