Class Mammalia Linnaeus, 1758 - mammals Subclass Prototheria Gill, 1872 - monotremes Order Monotremata Bonaparte, 1837 - monotremes Family Ornithorhynchidae Gray, 1825 - platypuses Genus Ornithorhynchus Blumenbach, 1800 - duck-billed platypus 1 Ornithorhynchus anatinus (Shaw, 1799) - platypus