Hexapods - insects see Epiclass Hexapoda Latreille, 1825
   Class Insecta Linnaeus, 1758 - insects
     Subclass Dicondylia Haeckel, 1866
       Infraclass Pterygota Lang, 1888
         Division Ephemeroptera Hyatt & Arms, 1890
           Order Ephemeroptera Hyatt & Arms, 1891 - mayflies
             Suborder Pisciforma
               Superfamily Heptagenioidea
                 1 Family Isonychiidae Burks, 1953
                 2 Family Oligoneuriidae Ulmer, 1914
                 3 Family Pseudironidae
                 4 Family Arthropleidae Balthasar, 1937
                 5 Family Heptageniidae Needham, 1901