Class Mammalia Linnaeus, 1758 - mammals
   Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 - tribotherians see Clade Boreosphenida Luo, Cifelli & Kielan-Jaworowska 2001
     Order †Aegialodontia Butler, 1978 [monotypic]
       Family †Aegialodontidae Kermack, 1967
         1 Genus †Aegialodon Kermack et al., 1965 [monotypic]
         2 Genus †Kielantherium Dashzeveg, 1975 [monotypic]