Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct.
       Vertebrata Lamarck, 1801 - vertebrates see Infraphylum Vertebrata Lamarck, 1801
         Superclass Petromyzontomorphi [monotypic]
           Class Petromyzontida [monotypic] - lampreys see Class Petromyzonti
             Order Petromyzontiformes Berg, 1940 - lampreys
               Family Petromyzontidae Bonaparte, 1831, sedis mutabilis - lampreys
                 Subfamily Lampetrinae
                   1 Genus Caspiomyzon Berg, 1906 [monotypic]
                   2.1 Genus Tetrapleurodon Creaser & Hubbs, 1922
                   2.2.1 Genus Entosphenus Gill, 1862
                   2.2.2.1 Genus Eudontomyzon Regan, 1911
                   2.2.2.2.1 Genus Lampetra Bonnaterre, 1788
                   2.2.2.2.2 Genus Lethenteron Creaser & Hubbs, 1922