Mammaliaformes Rowe 1988 [crown] Class Mammalia Linnaeus, 1758 - mammals Subclass Theriiformes Rowe, 1988 see Division Theriiformes Rowe, 1988 Infraclass †Triconodonta Osborn, 1888 see Order Triconodonta Osborn, 1888 Family †Triconodontidae Marsh, 1887 Subfamily †Alticonodontinae Fox, 1976 Genus †Alticonodon Fox, 1969