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 †Yohelcionelloidea nom. null.
see Superfamily Yochelcionelloidea Runnegar & Jell, 1976
1 Family †Yochelcionellidae Runnegar & Jell, 1976
2 Family †Trenellidae Parkhaev, 2001
3 Family †Stenothecidae Runnegar & Jell, 1980