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 †Pteridospermatophyta Meyen
         Class †Pachytestopsida Doweld (2001)
           Order †Pachytestales Doweld (2001)
             Family †Stephanospermaceae Doweld (2001) [monotypic]
               1 Genus †Stephanospermum Brongn. (1874)