Phylum Schizoramia Bergström, 1976a see Phylum Arthropoda Siebold, 1848
   Superclass Crustaceomorpha Chernyshev, 1960 see [unranked] Crustaceomorpha Chernyshev, 1960
     Class †Pseudocrustacea Størmer, 1944
       Order †Waptiida Størmer, 1944, nom. corr. see Order Hymenocarina Clarke, 1882
         Family †Waptiidae Walcott, 1912, nom. corr.
           Genus †Plenocaris Whittington, 1974
             †Plenocaris plena