Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Pisces
       Class Actinopterygii Woodward, 1891 - ray-finned fishes
         Order Notacanthiformes Goodrich, 1909 - spiny eels
           Family Halosauridae - halosaurs
           Family Lipogenyidae see Family Notacanthidae Rafinesque, 1815
           Family Notacanthidae Rafinesque, 1815 - spiny eels