Domain Eucaryota
   Subdomain Chlorota Doweld (2001)
     Kingdom Chlorobiota C.Jeffrey ex Doweld (2001) - plants see Subkingdom Viridiplantae Caval.-Sm. (1981)
       Subkingdom Pteridobiotina Britton & A. Br. (1896)
         Superphylum Cycadophytanae Doweld (2001)
           Phylum Pinophyta Cronquist, Takht. & Zimmerm. ex Reveal (1996) see Class Pinopsida Burnett (1835)
             Class †Voltziopsida Doweld (2001) see Class Pinopsida Burnett (1835)
               Order †Voltziales Andreánszky (1954)
                 1 Family †Bartheliaceae G.W.Rothwell & Mapes (2001)
                 2 Family †Otoviciaceae Doweld (2001)
                 3 Family †Walchiaceae Stur (1875)
                 4 Family †Thucydiaceae Hernandez-Castillo, Rothwell & G. Mapes (2001)
                 5 Family †Majonicaceae Clement-Westerhof (1987)
                 6 Family †Voltziaceae Arnold (1947)
                 7 Family †Swedenborgiaceae Zimmerm. (1959) see Family Voltziaceae Arnold (1947)