[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Algae L. (1753) see [unranked] Algae
     Phylum Phaeophycota see Class Phaeophyceae Hansgirg (1886)
       Class Phaeophyceae Hansgirg (1886) - brown algae
         Order Chordariales
           Family Ralfsiaceae Farlow (1881)
             Genus Pseudolithoderma Svedelius, in Engl. & Prantl (1911)
               Pseudolithoderma extensum (P.L. Crouan & H.M. Crouan) S. Lund (1959)