Kingdom [Animalia] Linnaeus, 1758 - animals
   Subkingdom Metazoa Haeckel, 1874 see Kingdom Animalia Linnaeus, 1758
     Division Eumetazoa Butschli, 1910 see Subkingdom Eumetazoa Butschli, 1910
       Subdivision Bilateralia
         Phylum Chordata Bateson, 1885 - chordates
           Subphylum Vertebrata Cuvier, 1812 - vertebrates
             Class Mammalia Linnaeus, 1758 - mammals
               Subclass Prototheria Gill, 1872 - monotremes
                 Order Monotremata Bonaparte, 1837 - monotremes
                   Family Ornithorhynchidae Gray, 1825 - platypuses
                     1 Genus Ornithorhynchus Blumenbach, 1800 - duck-billed platypus