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
           1 Superfamily †Retzioidea Waagen, 1883
           2 Superfamily †Mongolospiroidea Alekseeva, 1981
           3 Superfamily †Rhynchospirinoidea Schuchert, 1929