Class Mammalia Linnaeus, 1758 - mammals Subclass Acrotheria Averianov & Lopatin, 2011 Infraclass Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975 Superlegion Theria Parker & Haswell, 1897 see Subclass Theria Parker & Haswell, 1897 Legion Metatheria Huxley, 1880 see Infraclass Metatheria Huxley, 1880