Kingdom Protoctista Hogg, 1860
   Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
       Subclass Rhizosoleniophycidae Round & R.M. Crawford (1990)
         Order Rhizosoleniales P.C.Silva (1962)
           1 Family Rhizosoleniaceae De Toni (1890)
           2 ?Family Acanthoceraceae (R.M. Crawford, 1990) see Family Acanthocerataceae R.M. Crawford & Round (1990)
           3 Family Attheyaceae R.M. Crawford & Round (1990)