Class Mammalia Linnaeus, 1758 - mammals Count: - Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 - tribotherians see Clade Boreosphenida Luo, Cifelli & Kielan-Jaworowska 2001 Count: - Infraclass Metatheria Huxley, 1880 Count: - 1 Order †Deltatheroida Kielan-Jaworowska, 1982 Count: - 2 Order †Asiadelphia Trofimov & Szalay, 1993 Count: - 3 Cohort Marsupialia Jameson, 1818 - marsupials Count: -