Vertebrata Cuvier, 1812 - vertebrates
 see Infraphylum Vertebrata Lamarck, 1801
  
 Gnathostomata
    
 Teleostomi Bonaparte, 1836
      
 Tetrapoda Hatschek & Cori 1896 [Gauthier, Kluge & Rowe 1988], nom. cl. inval.
 see Clade Tetrapoda Hatschek & Cori 1896 [Laurin 2020]
        
 Amniota Haeckel, 1866 [Gauthier, Kluge & Rowe 1988], nom. cl. inval. - amniotes
 see Clade Amniota Haeckel 1866 [Laurin & Reisz 2020]
          
 Class Mammalia Linnaeus, 1758 - mammals
            
 Subclass Theria Parker & Haswell, 1897
              
 Theria of Metatherian-Eutherian grade
                
 Infraclass Eutheria Gill, 1872
                  
 Order Cetacea Brisson, 1762 - whales, dolphins, and porpoises
 see Infraorder Cetacea Brisson, 1762
                    
 1 Suborder †Archaeoceti Flower, 1883
 see Infraorder Archaeoceti Flower, 1883
                    
 2 Suborder Odontoceti Flower, 1867 - toothed whales
 see Parvorder Odontoceti Flower, 1867
                    
 3 Suborder Mysticeti Cope, 1891 - baleen whales
 see Parvorder Mysticeti Cope, 1891