Mammaliaformes Rowe 1988
   [crown] Class Mammalia Linnaeus, 1758 - mammals
     Subclass Theriiformes Rowe, 1988 see Division Theriiformes Rowe, 1988
       Infraclass †Allotheria Marsh, 1880 see Clade Allotheria Marsh 1880
         Order †Multituberculata Cope, 1884
           Suborder †Cimolodonta McKenna, 1975
             Superfamily †Ptilodontoidea Gregory & Simpson, 1926 (1887)
               Family †Ptilodontidae Gregory & Simpson, 1926 (1887)
                 Subfamily †Neoplagiaulacinae Ameghino, 1890 see Family Neoplagiaulacidae Ameghino, 1890
                   Genus †Ectypodus Matthew & Granger, 1921