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 †Deltatheroida Kielan-Jaworowska, 1982 see Order Deltatheroida Kielan-Jaworowska, 1982
         1 Family †Deltatheridiidae Gregory & Simpson, 1926
         2 ?Genus †Atokatheridium Kielan-Jaworowska & Cifelli, 2001 [monotypic]
         3 Genus †Khuduklestes Nessov, Sigogneau-Russell & Russell, 1994, incertae sedis [monotypic]
         4 Genus †Oxlestes Nessov, 1982, incertae sedis [monotypic]