Mammaliaformes Rowe 1988 [crown] Mammalia Linnaeus 1758 [Rowe 1988], nom. cl. inval. see Class Mammalia Linnaeus, 1758 Prototheria Gill 1872 [O'Leary, Allard, Novacek, Meng & Gatesy 2004] see Subclass Prototheria Gill, 1872 [crown] Monotremata Bonaparte 1837 [Rowe 1988] see Order Monotremata Bonaparte, 1837 †Megalibgwilia robusta (Dun, 1895)