Mammalia Linnaeus, 1758 - mammals
   Cetacea Brisson, 1762 - whales, dolphins, and porpoises see Infraorder Cetacea Brisson, 1762
     Odontoceti Flower, 1867 - toothed whales see Parvorder Odontoceti Flower, 1867
       Physeteridae Gray, 1821 - sperm whales
         1 Kogia Gray, 1846 - pygmy and dwarf sperm whales
         2 Physeter Linnaeus, 1758 - sperm whale