[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925
     Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics
       Subclass Chaetocerotophycidae Round & R.M. Crawford (1990) see Class Mediophyceae Medlin & Kaczmarska (2004)
         Order Chaetocerotales Round & R.M. Crawford (1990)
           Family Chaetocerotaceae Ralfs (1861)
             Genus Chaetoceros Ehrenb. (1844)
               Chaetoceros didymus Ehrenberg (1845)
                 Chaetoceros didymus var. protuberans (Lauder) Gran & Yendo