[Bilateria] Hatschek, 1888 - bilaterians see Subkingdom Bilateria Hatschek, 1888
   ecdysozoans see Clade Ecdysozoa Aguinaldo, Turbeville, Linford, Rivera, Garey, Raff & Lake 1997, nom. cl. inval.
     Arthropoda Siebold, 1848 - arthropods
       Arachnomorpha Heider, 1913
         Order †Limulavida Walcott, 1911
           1 Genus †Sidneyia Walcott, 1911