Class Mammalia Linnaeus, 1758 - mammals
   Subclass †Allotheria Marsh, 1880
     Order †Multituberculata Cope, 1884
       Suborder †Cimolodonta McKenna, 1975
         Family †Eucosmodontidae Jepsen, 1940, incertae sedis
           1 Genus †Eucosmodonᵀ Matthew & Granger, 1921
           2 Genus †Stygimys Sloan & Van Valen, 1965
           3 ?Genus †Clemensodon Krause, 1992 [monotypic]