Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
     Pisces
       1 Class †Pituriaspida Young, 1991 see Order Pituriaspida Young, 1991
       2 Class Mixini see Class Myxini Jaekel, 1911
       3 Class †Pteraspidomorphi Goodrich, 1909 see Class Pteraspidomorpha
       4 Class Cephalaspidomorphi Kiaer & Stensiö, 1920 see Class Osteostraci Lankester, 1868
       5 Class †Placodermi McCoy, 1848
       6 Class Chondrichthyes Huxley, 1880 - cartilaginous fishes
       7 Class †Acanthodii Owen, 1846 - acanthodians
       8 Class Actinopterygii Woodward, 1891 - ray-finned fishes see Clade Actinopterygii Woodward 1891 [Moore & Near 2020]
       9 Class Sarcopterygii Romer, 1955 - lobe-finned fishes and tetrapods see [unranked] Sarcopterygii Romer, 1955