Class Mammalia Linnaeus, 1758 - mammals Subclass Acrotheria Averianov & Lopatin, 2011 1 Infraclass †"Triconodonta" Osborn, 1888 [paraphyletic] see Order Triconodonta Osborn, 1888 1.n Infraclass †"Symmetrodonta" Simpson, 1925 [paraphyletic] 1.n.n1 Infraclass †Cladotheria McKenna, 1975 [monotypic] see Clade Cladotheria McKenna 1975 1.n.n2 Trechnotheria McKenna 1975 1.n.n2.2 Infraclass Zatheria McKenna, 1975 see Clade Zatheria McKenna 1975