Phylum Mollusca Linnaeus, 1758 - molluscs
   Conchifera Gegenbaur, 1878 see Subphylum Conchifera Gegenbauer, 1878
     Cyrtosoma
       Class Gastropoda Cuvier, 1795 - snails and slugs
         Subclass †Archaeobranchia Parkhaev, 2001
           Order †Helcionelliformes Golikov & Starobogatov, 1975
             Superfamily †Helcionelloidea Wenz, 1938 see Superfamily Scenelloidea Miller, 1889
               Family †Helcionellidae Wenz, 1938 see Family Scenellidae Miller, 1889
                 01 Genus †Absidaticonus Yue, 1984
                 02 Genus †Aequiconus Parkhaev, 2001
                 03 Genus †Anuliconus Parkhaev, 2001
                 04 Genus †Asperconella Landing, 1996
                 05 Genus †Bemella Missarzhevsky, 1969
                 06 Genus †Calyptroconus Parkhaev, 2001
                 07 Genus †Ceratoconus Chen & Chang, 1980, nom. illeg.
                 08 Genus †Chabaktiella Missarzhevskij, 1981
                 09 Genus †Chuiliella Gubanov & Peel, 2001
                 10 Genus †Codonoconus Chen Yiyuan & Chang Shushen, 1980
                 11 Genus †Daedalia Parkhaev, 2001
                 12 Genus †Emarginoconus Yu Wen, 1979
                 13 Genus †Fenqiaronia Parkhaev, 2001
                 14 Genus †Hampilina Kobayashi, 1958
                 15 Genus †Helcionella Grabau & Shimer, 1909
                 16 Genus †Igorella Missarzhevsky, 1969
                 17 Genus †Ilsanella Missarzhevskij, 1981
                 18 Genus †Lenoconus Vassiljeva, 1990
                 19 Genus †Marocella Geyer, 1986
                 20 Genus †Miroconulus Parkhaev, 2001
                 21 Genus †Obtusoconus Yu Wen, 1979
                 22 Genus †Pararaconus Runnegar, 1990
                 23 Genus †Pseudoscenella Starobogatov & Moskalev, 1987
                 24 Genus †Randomia Matthew, 1899
                 25 Genus †Salanyella Missarzhevskij, 1981
                 26 Genus †Scenella Billings, 1872
                 27 Genus †Securiconus Jiang, 1980
                 28 Genus †Tannuella Missarzhevskii, 1969
                 29 Genus †Truncatoconus Yu Wen, 1979
                 30 Genus †Tuoraconus Missarjevsky, 1989
                 31 Genus †Yangtzeconus Yu Wen, 1979