[Arthropoda] Siebold, 1848 - arthropods see Phylum Arthropoda Siebold, 1848
   Arachnomorpha Heider, 1913
     †Trilobitomorpha Størmer, 1944 see Superclass Trilobitomorpha Størmer, 1944
       †Helmetiida Novozhilov, 1969 see Order Helmetiida Novozhilov, 1969
         Genus †Skioldia X. Hou & J. Bergström, 1997