Metazoa see Kingdom Animalia Linnaeus, 1758
   Gastraeozoa
     Trochaeozoa see [unranked] Bilateria Hatschek, 1888
       Gastroneuralia Ulrich, 1951
         Aschelminthes Grobben, 1910 see [unranked] Protostomia Grobben, 1908
           1 Phylum Rotifera Cuvier, 1798 - rotifers see Phylum Syndermata Ahlrichs, 1995
           2 Phylum Acanthocephala Kohlreuther, 1771 - acanthocephalans see [unranked] Acanthocephala Kohlreuther, 1771
           3 Phylum Chaetognatha Leuckart, 1854 - chaetognaths
           4 Phylum Nematoda Gegenbaur, 1859 - round worms
           5 Phylum Nematomorpha Vejdovsky, 1886 - horsehair worms
           6 Phylum Kinorhyncha Reinhard, 1887 - kinorhynchs
           7 Phylum Loricifera Kristensen, 1983 - loriciferans
           8 Phylum Priapulida Delage & Hérouard, 1897 - priapulids
           9 Phylum Gastrotricha Metschnikoff, 1864 - gastrotrichs