Parent taxon: Gastropoda according to P. Bouchet et al. 2005
Sister taxa: Achatina, Acteonoidea, Admetidae, Alamirifica, Amalthea, Amphigastropoda, Archaeobranchia, Architectonicidae, Auroraella, Beekmanoceras, Bellerophontida, Brachycerithium, Briardia, Bucardites, Buccinites, Bulimella, Bulimulidae, Bulimus, Bullaea, Caenogastropoda, Capulus sellardsi, Catubrina, Cavolinioidea, Chartrionella, Chippewaella, Chlathrus, Chrysodomidae, Chuchleconus, Cithna, Cocculiniformia, Cyclostoma, Deroceras, Dextrobranchia, Dicosmus, Doliidae, Dorcasiidae, Elmira, Eogastropoda, Eunerinea, Fruiticicoiidae, Galeodea schencki, Galericulus, Geinitzia, Geinitzia carinata, Globulitopa, Gordenella, Gryphellina, Gundlachia, Hecatastoma, Helicarionoidea, Helicidae, Helicites, Helictes, Helminthoglyptidae, Holopea incola, Holyneconcha, Hyalaea, Hyalinia, Hyrcania, Isaea, Iteria, Itieria, Jeffreysia, Juliidae, Liris, Lovonemetrida, Luoguella, Luoguispira, Lymnaea, Lysechinus, Lysechinus incongruens, Mahajangina, Mathildidae, Microceras, Microcochlis, Mitrularia, Monotigma, Neomphaliones, Neptuneidae, Nerinea, Neritaemorpha, Neritimorpha, Neritites, Notodelphinula, Opisthobranchiata, Orthogastropoda, Patellogastropoda, Patelloidea, Pectinibranchia, Pejona, Peraubium, Permoplanorboidea, Phorus, Pitonnellus, Planorboidea, Platyostomella, Platystoma, Plectopyloidea, Pleurotomaria verticillata, Pleurotomaria verticillata, Pleurotomaria viola, Plicatusidae, Polygyridae, Pragoserpulinidae, Prasinidae, Prosobranchia, Pseudobrochidium, Pseudotylostoma, Ptenoglossa, Pteronotus, Pteropoda, Pulmonata, Pupillacea, Pyramidellidae, Pythia, Rhytidopilidae, Rotellina, Rugoplanorboidella, Scalariidae, Serpulopsis, Spiraxidae, Spirgvaleia, Streptoneura, Stuorilda, Subulinidae, Suprazonalia, Taeniodomus, Thatcheriidae, Tirolthilda, Tornatella, Tortifusus, Toxonema, Tripartella, Trochifusus, Trochiletes, Trochopsis, Trochotremaria, Trochulus, Turbo guadalupensis, Turbo texana, Urocoptidae, Valvata, Vespertilio, Vetigastropoda, Wellingtonia, Zlichovia
Subtaxa: Opisthonema
Type: Opisthonema
Ecology: epifaunal
Distribution: found only at BaoTa (Pagoda) Fm., GaoQiao, ZhengBa Co., ShanXi Prov., China (Ordovician of China)