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 †Caytoniopsida H.H.Thomas ex Frenguelli (1946) [monotypic]
           Order †Caytoniales E.Wulff (1926) [monotypic]
             Family †Caytoniaceae Kräusel (1926)
               1 Genus †Amphorispermum T.M.Harris (1932)
               2 Genus †Caytonia H.H.Thomas (1925), incertae sedis
               3 Genus †Caytonanthus T.M.Harris (1937)
               4 Genus †Sagenopteris C.Presl (1838)
               5 Genus †Scoresbya T.M.Harris (1932)