Class Mammalia Linnaeus, 1758 - mammals
   Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 - tribotherians see Clade Boreosphenida Luo, Cifelli & Kielan-Jaworowska 2001
     Infraclass Eutheria Gill, 1872
       Genus †Montanalestes Cifelli, 1999, incertae sedis [monotypic]
         1 †Montanalestes keeblerorum Cifelli, 1999