[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 Fragilariophyceae Round (1990) - araphid, pennate diatoms see Class Bacillariophyceae Haeckel (1878)
       Subclass Fragilariophycidae Round (1990) - core araphid diatoms
         Order Thalassionematales Round (1990)
           Family Thalassionemataceae Round (1990)
             Genus Thalassiothrix Cleve & Grunow (1880)
               Thalassiothrix longissima Cleve & Grunow