[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 Rhizosoleniophycidae Round & R.M. Crawford (1990)
         Order Rhizosoleniales P.C.Silva (1962)
           Family Rhizosoleniaceae De Toni (1890)
             Genus Guinardia H. Perag. (1892)
               1 Guinardia cylindrus (P.T. Cleve) G.R. Hasle
               2 Guinardia flaccida (Castracane) H. Peragallo (1892)