Phylum Brachiopoda Duméril, 1806 - brachiopods
   Subphylum Rhynchonelliformea Williams et al., 1996
     Class Rhynchonellata Williams et al., 1996
       Order †Athyridida Boucot et al., 1964
         Suborder †Retziidina Boucot et al., 1964
           Superfamily †Rhynchospirinoidea Schuchert, 1929
             1 Family †Rhynchospirinidae Schuchet, 1929
             2 Family †Parazygidae Alvarez et al., 1998