 Phylum Chordata Bateson, 1885 - chordates
 Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
 see Infraphylum Vertebrata Lamarck, 1801
 Subphylum Vertebrata Cuvier, 1812 - vertebrates
 see Infraphylum Vertebrata Lamarck, 1801
     Class Mammalia Linnaeus, 1758 - mammals
 Class Mammalia Linnaeus, 1758 - mammals
       Order Monotremata Bonaparte, 1837 - monotremes
 Order Monotremata Bonaparte, 1837 - monotremes
         Family †Kollikodontidae Flannery, Archer, Rich & Jones, 1995
 Family †Kollikodontidae Flannery, Archer, Rich & Jones, 1995
         Family Ornithorhynchidae Gray, 1825 - platypuses
 Family Ornithorhynchidae Gray, 1825 - platypuses
         Family Tachyglossidae Gill, 1872 - spiny anteaters
 Family Tachyglossidae Gill, 1872 - spiny anteaters