Mammalia Linnaeus 1758 [Rowe 1988], nom. cl. inval. see Clade Mammalia Linnaeus 1758 [Rowe 2020]
Count: [*†*] 6o;1f;14g; †7o;26f;156g;4s
   Metatheria Huxley 1880 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Infraclass Metatheria Huxley, 1880
  Count: [*†*] 6o;1f;14g; †6o;26f;143g;4s
     [Order] †Deltatheroida Kielan-Jaworowska, 1982
    Count: [†*] †8g
       Genus †Deltatheridium Gregory & Simpson, 1926
      Count: -