Phylum Chordata Bateson, 1885 - chordates
   Subphylum Vertebrata Cuvier, 1812 - vertebrates
     Pisces
       Class Actinopterygii Woodward, 1891 - ray-finned fishes
         Order Cyprinodontiformes Berg, 1940 - killifishes
           Family Anablepidae Garman, 1895 - four-eyed fish
           Family Aplocheilidae Bleeker, 1860 - killifishes
           Family Cyprinodontidae Gill, 1865 - pupfishes
           Family Goodeidae Jordan, 1923 - goodeids
           Family Poeciliidae Garman, 1895 - live-bearers