[Phylum] Chordata Bateson, 1885 - chordates
   Subphylum Craniata auct.
     Infraphylum Vertebrata Lamarck, 1801 - vertebrates
       1 Class Petromyzontida [monotypic] - lampreys see Class Petromyzonti
       2 Superclass †Pteraspidomorphi Goodrich, 1909 [monotypic]
       3 Superclass †Anaspidomorphi
       4 Superclass †Thelodontomorphi Jaekel, 1911 [monotypic]
       5 Superclass †Osteostracomorphi
       6 Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates