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 1 Genus †Alticonodon Fox, 1969