Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
   Subkingdom Pteridobiotina Britton & A. Br. (1896)
     Superdivision Pteridophytanae Doweld (2001) [monotypic] see Superphylum Pteridophytanae Doweld (2001)
       Division Monilophyta Cantino & Donoghue
         Class Marattiopsida Doweld (2001) see Subclass Marattiidae Klinge (1882)
           Order †Zygopteridales Emberger (1944)
             Family †Psalixochlaenaceae Holmes (1981)
               Genus †Protothamnopteris R.Beck (1920)