[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Phylum Platyhelminthes Gegenbaur, 1859 - flatworms
     Class Turbellaria Ehrenberg, 1831 - planarians see Subphylum Turbellaria Ehrenberg, 1831
       Order Rhabdocoela Ehrenberg, 1831 see Infraclass Rhabdocoela Ehrenberg, 1831
         Suborder Typhloplanida
           Family Trigonostomidae Graff, 1905 (1882)
             Genus Trigonostomum Schmidt, 1852
               01 Trigonostomum armatum (Jensen, 1878) Southern, 1912
               02 Trigonostomum breitfussi (von Graff, 1905)
               03 Trigonostomum brunchorsti von Graff, 1905, nom. inq.
               04 Trigonostomum coronatum (von Graff, 1882) von Graff, 1913
               05 Trigonostomum intermedium (Attems, 1896)
               06 Trigonostomum mirabile (Pereyaslawzewa, 1892) von Graff, 1913
               07 Trigonostomum penicillatum (O. Schmidt, 1857) Micoletzky, 1910
               08 Trigonostomum piriforme (Pereyaslawzewa, 1892) von Graff, 1905, nom. inq.
               09 Trigonostomum quadrifolium Riedl, 1954 see Trigonostomum coronatum (von Graff, 1882) von Graff, 1913
               10 Trigonostomum setigerum O. Schmidt, 1852
               11 Trigonostomum venenosum (Uljanin, 1870)