living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Nemertea Schultze, 1851 - ribbon worms
           Class Anopla see Phylum Nemertea Schultze, 1851
             Order Palaeonemertea Hubrecht, 1879 see Phylum Nemertea Schultze, 1851
               Family Cephalothricidae McIntosh, 1874
                 Genus Procephalothrix Wijnhoff, 1913
                   Procephalothrix spiralis (Coe, 1930)