Class Mammalia Linnaeus, 1758 - mammals
   Subclass Acrotheria Averianov & Lopatin, 2011
     Infraclass Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975
       Superlegion "Prototheria" Gill, 1872 [paraphyletic] see Subclass Prototheria Gill, 1872
         1 Legion †"Prototribosphenida" Wible, Rougier, Novacek, McKenna & Dashzeveg, 1995 [paraphyletic] see Clade Prototribosphenida Wible, Rougier, Novacek, McKenna & Dashzeveg 1995
         2 Legion Australosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 see Clade Australosphenida Luo, Cifelli & Kielan-Jaworowska 2001