Kingdom [Plantae] Haeckel (1866) - plants
   Division Gymnospermophyta Cleal (1994) - seed plants see Infraphylum Gymnospermae auct.
     Class †
       1 Order †Calamopityales Němejc (1963) [monotypic]
       2 Order †Callistophytales Rothwell (1981) [monotypic]
       3 Order †Peltaspermales Delevoryas (1979)
       4 Order †Leptostrobales S.V.Meyen (1987) [monotypic] see Order Czekanowskiales Novák (1972)
       5 Order †Arberiales S.V.Meyen (1982) - glossopterids
       6 Order †Gigantonomiales [monotypic] - gigantopterids