protostomes see [unranked] Protostomia Grobben, 1908
   Spiralia Schleip, 1929 - spiralians see Superphylum Spiralia Schleip, 1929
     Lophotrochozoa Halanych, Bacheller, Aguinaldo, Liva, Hillis & Lake 1995 - lophotrochozoans
       1.1.1 Parenchymia
       1.1.2 [Phylum] Annelida Lamarck, 1809 - segmented worms
       1.2.1 Lophophorata Hyman, 1959
       1.2.2 [Phylum] Gastrotricha Metschnikoff, 1864 - gastrotrichs
       2 Tetraneuralia Wanninger 2009