Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Pteridobiotina Britton & A. Br. (1896)
     Superdivision Cycadophytanae Doweld (2001) see Superphylum Cycadophytanae Doweld (2001)
       Division Cycadophyta Bessey (1907)
         Class Cycadopsida Brongn. (1843)
           Subclass Zamiidae Doweld (2001)
             Order †Nilsoniales (1935), orth. inval. [monotypic] see Order Nilssoniales W.Zimm. (1930)
               Family †Nilsoniaceae Ziegensp. (1927), orth. inval. see Family Nilssoniaceae Ziegensp. (1925)
                 1 Genus †Androstrobus Schimp. (1870)
                 2 Genus †Beania Carruth. (1869)
                 3 Genus †Cycadoxylon Renault (1879)
                 4 Genus †Dirhopalostachys Pryn. ex Krassilov (1975)
                 5 Genus †Nilsonia Brongn. (1825), orth. inval. see Genus Nilssonia Brongn. (1825)
                 6 Genus †Nilssoniocladus T.Kimura & S. Sekido (1975)