Class Mammalia Linnaeus, 1758 - mammals
   Subclass †Allotheria Marsh, 1880
     Order †Multituberculata Cope, 1884
       Suborder †Cimolodonta McKenna, 1975
         Family †Microcosmodontidae Holtzman & Wolberg, 1977, incertae sedis
           1 Genus †Microcosmodonᵀ Jepsen, 1930