living organisms
 see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
  
 Superkingdom Eukaryotae
 see Domain Eukaryota Chatton, 1925
    
 Kingdom Animalia Linnaeus, 1758 - animals
      
 Subkingdom Eumetazoa Butschli, 1910
 see [unranked] Eumetazoa Bütschli, 1910
        
 Phylum Chordata Bateson, 1885 - chordates
          
 Subphylum Vertebrata Cuvier, 1812 - vertebrates
 see Infraphylum Vertebrata Lamarck, 1801
            
 Class Mammalia Linnaeus, 1758 - mammals
              
 Subclass Theria Parker & Haswell, 1897
                
 Infraclass Eutheria Gill, 1872
                  
 Order Perissodactyla Owen, 1848 - odd-toed ungulates
                    
 1 Family Equidae Gray, 1821 - horses, zebras, and asses
                    
 2 Family Tapiridae Gray, 1821 - tapirs
                    
 3 Family Rhinocerotidae Gray, 1821 - rhinoceroses