[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
         1 †Helmetiidae Simonetta & Delle Cave, 1975
         2.1 Genus †Tegopelte Simonetta & Delle Cave, 1975
         2.2.1 Genus †Skioldia X. Hou & J. Bergström, 1997
         2.2.2 Genus †Saperion Hou et al., 1991