Domain Eucaryota
   Subdomain Chlorota Doweld (2001)
     Kingdom Bacillariobiota Doweld (2001)
       Subkingdom Bacillariobiotina Doweld (2001)
         Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
           1 Class Bacillariophyceae Haeckel (1878) - pennates
           2 Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
           3 Class Fragilariophyceae Round (1990) - araphid, pennate diatoms see Class Bacillariophyceae Haeckel (1878)