Class Mammalia Linnaeus, 1758 - mammals
   Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 - tribotherians see Clade Boreosphenida Luo, Cifelli & Kielan-Jaworowska 2001
     Infraclass Metatheria Huxley, 1880
       Cohort Marsupialia Jameson, 1818 - marsupials
         Superorder "Ameridelphia" Szalay, 1982 [paraphyletic] see Clade Ameridelphia Szalay 1982
           Order "Didelphimorphia" Gill, 1872 [paraphyletic]
             Family †"Pediomyidae" Simpson, 1927 [monophyletic?]
               Genus †"Pediomys"ᵀ Marsh, 1889 [monophyletic?]
                 †"Pediomys" fassetti Rigby & Wolberg, 1987 see Leptalestes prokrejcii (Fox, 1979)