Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Class Mammalia Linnaeus, 1758 - mammals
       Order Cetacea Brisson, 1762 - whales, dolphins, and porpoises see Infraorder Cetacea Brisson, 1762
         Family †Acrodelphidae Abel, 1905 see Family Acrodelphinidae Abel, 1905, nom. dub.
         Family †Aetiocetidae Emlong, 1966
         Family †Agorophiidae Abel, 1913
         Family †Albireonidae Barnes, 1984
         Family Balaenidae Gray, 1821 - right whales
         Family Balaenopteridae Gray, 1864 - rorquals
         Family †Basilosauridae Cope, 1868
         Family †Cetotheriidae Brandt, 1872
         Family †Dalpiazinidae de Muizon, 1988
         Family Delphinidae Gray, 1821 - oceanic dolphins
         Family Eschrichtiidae Ellerman & Morrison-Scott, 1951 - gray whales
         Family †Kentriodontidae Slijper, 1936
         Family †Llanocetidae Mitchell, 1989
         Family Monodontidae Gray, 1821 - white whales
         Family †Odobenocetopsidae de Muizon, 1993
         Family Phocoenidae Gray, 1825 - porpoises
         Family Physeteridae Gray, 1821 - sperm whales
         Family Platanistidae Gray, 1846 - river dolphins
         Family Pontoporiidae Gray, 1870 - Franciscana, La Plata dolphin
         Family †Protocetidae Stromer, 1908
         Family †Remingtonocetidae Kumar & Sahni, 1986
         Family †Rhabdosteidae Gill, 1871 see Family Eurhinodelphinidae Abel, 1901
         Family †Squalodontidae Brandt, 1873 - shark-toothed dolphins
         Family †Waipatiidae Fordyce, 1994
         Family †Zignodelphidae
         Family Ziphiidae Gray, 1850 - beaked whales