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
         A Class †Moresnetiopsida Doweld (2001)
         B Class †Lyginopteridopsida Novák (1961)
         C Class †Pachytestopsida Doweld (2001)
         D Class †Phasmatocycadopsida Doweld (2001)
         E Class †Peltaspermopsida Doweld (2001)
         F Class †Arberiopsida Doweld (2001)
         G Class †Dyctiopteridiopsida A.V.Novikov & B. Barabasz-Krasny (2015), orth. inval. see Class Dictyopteridiopsida Doweld (2001)
         H Class †Pentoxylopsida D.D.Pant (1959) [monotypic]
         I Class †Caytoniopsida H.H.Thomas ex Frenguelli (1946) [monotypic]