Superphylum Deuterostomia Grobben, 1908 - deuterostomes see Infrakingdom Deuterostomia Grobben, 1908
   Phylum Chordata Bateson, 1885 - chordates
     Subphylum Craniata auct. see Subphylum Vertebrata Cuvier, 1812
       Vertebrata (Lamarck, 1801) - vertebrates see Subphylum Vertebrata Cuvier, 1812
         Myopterygii - myopterygians
           Superclass Gnathostomata Gegenbaur, 1874 - jawed vertebrates
             Grade Teleostomi Bonaparte, 1836
               Euteleostomi - bony vertebrates
                 Class Actinopterygii Woodward, 1891 - ray-finned fishes
                   Subclass Neopterygii Regan, 1923
                     Order Lepisosteiformes Hay, 1929 [monotypic] - gars
                       Family Lepisosteidae Cuvier, 1825 - gars
                         Genus Atractosteus Rafinesque, 1820
                           Atractosteus spatula Lacépède, 1803 - alligator gar