Bigyra Cavalier-Smith, 1998
   Subphylum Opalozoa Cavalier-Smith, 1992
     Infraphylum Bikosia Cavalier-Smith, 2013 [monotypic]
       Class Bikosea Cavalier-Smith, 2013
         Subclass Bicosidia Cavalier-Smith, 2006
           Superorder Cyathobodoniae Cavalier-Smith, 1993
             Order Bicoecida Grassé, 1926
               Family Bicosoecidae Stein, 1878
                 1 Genus Bicosoeca James-Clark, 1866
                 2 Genus Stephanocodon Pascher, 1942
                 3 Genus Poteriodendron Stein, 1878