Class Mammalia Linnaeus, 1758 - mammals Count: - Subclass Theria Parker & Haswell, 1897 Count: - Infraclass Tribosphenida McKenna, 1975 see Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 Count: - Supercohort Eutheria Gill, 1872 see Infraclass Eutheria Gill, 1872 Count: -