Mammalia Linnaeus 1758 [Rowe 2020] see Class Mammalia Linnaeus, 1758
   Theria Parker & Haswell 1897 [McKenna 1975] see Subclass Theria Parker & Haswell, 1897
     Metatheria Huxley 1880 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Infraclass Metatheria Huxley, 1880
       †Deltatheroida Kielan-Jaworowska 1982 see Order Deltatheroida Kielan-Jaworowska, 1982
         1 Genus †Sulestes Nessov, 1985
         2.1 Genus †Deltatheridium Gregory & Simpson, 1926
         2.2 Genus †Deltatheroides Gregory & Simpson, 1926