organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Domain eukaryotes see Domain Eukaryota Chatton, 1925
     alveolates Cavalier-Smith see [unranked] Alveolata Cavalier-Smith, 1991
       Phylum Ciliophora Doflein, 1901 - ciliates
         Subphylum Intramacronucleata Lynn, 1996 - amphiesmates
           Class Oligohymenophorea de Puytorac et al., 1974 - oligohymenophoreans
             Subclass Peniculia Fauré-Fremiet, 1956
               Order Peniculida Fauré-Fremiet, 1956
                 Suborder Parameciina Jankowski, in Small & Lynn, 1985 see Order Urocentrida Jankowski, 1980
                   Family Urocentridae Claparède & Lachmann, 1858
                     Genus Urocentrum Nitzsch, 1827