[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Kingdom Animalia Linnaeus, 1758 - animals
     Branch Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
       Division Bilateria Hatschek, 1888 see Subkingdom Bilateria Hatschek, 1888
         Subdivision Protostomia Grobben, 1908 see Infrakingdom Protostomia Grobben, 1908
           Section Acoelomata
             Phylum Gnathostomulida Ax, 1956 - gnathostomulids
               Order Filospermoidea Sterrer, 1972
                 Genus Pterognathia Sterrer, 1966