Kingdom Protoctista Hogg, 1860
Count: [p] 36p;91c;87o;183f;507g;35s;2v
   Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844)
  Count: [f] 4c;41o;83f;204g
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
    Count: 20o;33f;85g
       Subclass Thalassiosirophycidae Round & R.M. Crawford (1990) see Class Mediophyceae Medlin & Kaczmarska (2004)
      Count: [f] 1o;4f;11g
         Order Thalassiosirales Glezer & I.V. Makarova (1986)
        Count: [f] 4f;11g
           Family Thalassiosiraceae M. Lebour (1930), nom. cons.
          Count: 5g
             Genus Thalassiosira Cleve (1873)
            Count: -