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
         Myopterygii Janvier, 1978 - myopterygians
           Superclass †Thelodonti Jaekel, 1911 [monotypic] - thelodonts see Superclass Thelodontomorphi Jaekel, 1911
             Class †Thelodonti Jaekel, 1911
               Order †Furcacaudiformes Wilson & Caldwell, 1998 - fork-tailed thelodonts
                 Family †Furcacaudidae Wilson & Caldwell, 1998
                   1 Genus †Canonia Vieth, 1980
                   2 Genus †Cometicercus Wilson & Caldwell, 1998
                   3 Genus †Drepanolepis Wilson & Caldwell, 1998
                   4 Genus †Furcacauda Wilson & Caldwell, 1998
                   5 Genus †Sphenonectris Wilson & Caldwell, 1998