[Arthropoda] Siebold, 1848 - arthropods see Phylum Arthropoda Siebold, 1848
   Arachnomorpha Heider, 1913
     †Trilobitomorpha Størmer, 1944 see Superclass Trilobitomorpha Størmer, 1944
       1 †Trilobita Walch, 1771 - trilobites see Class Trilobita Walch, 1771
       2 †Petalopleura Hou & Bergström, 1997 see Subclass Petalopleura Hou & Bergström, 1997
       3 †Naraoiidae Walcott, 1912
       4 †Helmetiida Novozhilov, 1969 see Order Helmetiida Novozhilov, 1969