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 Gnathostomata Gegenbaur, 1874 - jawed vertebrates
             Grade Teleostomi Bonaparte, 1836 see Clade Pan-Osteichthyes Rowe 2004 [Moore & Near 2020]
               Euteleostomi - bony vertebrates see Clade Osteichthyes Huxley 1880 [Moore & Near 2020]
                 Class Actinopterygii Woodward, 1891 - ray-finned fishes see Clade Actinopterygii Woodward 1891 [Moore & Near 2020]
                   Subclass Neopterygii Regan, 1923
                     Division Teleostei Müller, 1845
                       Elopocephala Arratia, 1999 see Supercohort Teleocephala de Pinna, 1996
                         Subdivision Elopomorpha Greenwood et al., 1966 see Cohort Elopomorpha Greenwood et al., 1966
                           Order Anguilliformes Berg, 1943 - eels
                             Suborder Anguilloidei
                               Family Heterenchelyidae Regan, 1912 - mud eels
                                 Genus Pythonichthys Poey, 1868