It is part of the subfamily Globicephalinae, and its closest living relatives are Risso's dolphin, the melon-headed whale (Peponocephala electra), the pygmy killer whale (Feresa attenuata), the pilot whales (Globicephala spp.), and possibly the snubfin dolphins (Orcaella spp.).[8] One subspecies was proposed by Paules Edward Pieris Deraniyagala in 1945, P. c. meridionalis, though there was not sufficient justification, and William Henry Flower suggested in 1884 and later abandoned a distinction between northern and southern false killer whales; there are currently no recognized subspecies.[9] However, individuals in populations around the world can have different skull structures and vary in average length, with Japanese false killer whales being 10–20% larger than South African false killer whales.[3][10] It can hybridize with the bottlenose dolphin (Tursiops truncatus) to produce fertile offspring called "wholphins".[7][11]