Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Superclass Agnatha Haeckel, 1895 see Class Agnatha Cope, 1889
       1 Class †Diplorhina Haeckel, 1895 see Class Pteraspidomorphi Goodrich, 1909
       2 Class Monorhina Haeckel, 1895 see Class Cephalaspidomorphi Moy-Thomas & Mile, 1971