This overview lists proposed changes in the taxonomy of gastropods at the family level and above. There have been many changes in the way various groups of snails and slugs are classified.
Changes in subfamilies are outlined in the respective articles about each particular family. Unchanged taxa are not listed here.
In one of the largest recent changes (affecting the most species of gastropods), Klussmann-Kolb et al. (2008) showed that the traditional classification of the Euthyneura needed to be reconsidered. The change was subsequently made by Jörger et al. (2010), who redefined the major groups within the Heterobranchia.
A great number of major changes have been made within the classification of the Conoidea since 2011.
Significant taxonomies Systems of classification are primarily of value to malacologists (people who study mollusks) and other biologists. Biological classification schemes are not merely a convenience, they are an attempt to show the actual phylogeny (the evolutionary relatedness) within a group of organisms. Thus, a taxonomy can be seen as an attempt to elucidate part of the tree of life, a phylogenetic tree.
Gastropods are a taxonomic class of animals which consists of snails and slugs of every kind, from the land, from freshwater, and from saltwater.
Ponder & Lindberg, 1997 Towards a phylogeny of gastropod molluscs: an analysis using morphological characters. was published by Winston Ponder and David R. Lindberg in 1997.Ponder W. & Lindberg D. R. (1997). "Towards a phylogeny of gastropod molluscs: an analysis using morphological characters". Zoological Journal of the Linnean Society 119(2): 83-265.
This taxonomy assigns the various Gastropods into ranked categories, such as sub-orders and families, but does not address the classification of genera or individual species. This classification scheme is based on the molluscs' internal and external shapes and forms, but did not take into account any analysis of their DNA or RNA.
Ponder & Lindberg (1997) used only four families to analyze the Euthyneura. Further work by Dayrat & Tillier (2002)Dayrat B. & Tillier S. (2002). "Evolutionary relationships of euthyneuran gastropods (Mollusca): a cladistic re-evaluation of morphological characters". Zoological Journal of the Linnean Society 135(4): 403-470. provided a great deal of detail about the relationships between within the Euthyneura.
Ponder & Lindberg (1997) did not use Linnean taxonomical ranks in their work, but the results of their paper were widely adapted and used with Linnean taxonomical ranks by other authors.
Class Gastropoda Cuvier, 1797 Incertæ sedis Order Bellerophontinaka (fossil) Order Mimospirina (fossil) Subclass Eogastropoda Ponder & David R. Lindberg, 1996 (earlier: Prosobranchia) Order Euomphalida de Koninck 1881 (fossil) Superfamily Macluritoidea Superfamily Euomphaloidea Superfamily Platyceratoidea
Order Patellogastropoda Lindberg, 1986 (true limpets) Suborder Patellina Van Ihering, 1876 Superfamily Patelloidea Rafinesque, 1815 Suborder Nacellina David R. Lindberg, 1988 Superfamily Acmaeoidea Carpenter, 1857 Superfamily Nacelloidea Thiele, 1891 Suborder Lepetopsina McLean, 1990 Superfamily Lepetopsoidea McLean, 1990 Subclass Orthogastropoda Ponder & David R. Lindberg, 1996 (earlier Prosobranchia, Opisthobranchia) Incertæ sedis Order Murchisoniina Cox & Knight, 1960 (fossil) Superfamily Murchisonioidea Koken, 1889 Superfamily Loxonematoidea Koken, 1889 Superfamily Lophospiroidea Wenz, 1938 Superfamily Straparollinoidea Grade Subulitoidea Lindström, 1884 Superorder Cocculiniformia Haszprunar, 1987 Superfamily Cocculinoidea Dall, 1882 Superfamily Lepetelloidea Dall, 1882 (deep sea limpets) Superorder "Hot Vent Taxa" Ponder & David R. Lindberg, 1997 Order Neomphaloida Sitnikova & Starobogatov, 1983 Superfamily Neomphaloidea McLean, 1981 (hydrothermal vents limpets) Superfamily Peltospiroidea McLean, 1989 Superorder Vetigastropoda Salvini-Plawen, 1989 (limpets)
Superfamily Fissurelloidea Fleming, 1822 (keyhole limpets) Superfamily Haliotoidea Rafinesque, 1815 (abalones) Superfamily Lepetodriloidea McLean, 1988 (hydrothermal vent limpets) Superfamily Pleurotomarioidea Swainson, 1840 (slit shells) Superfamily Seguenzioidea Verrill, 1884 Superfamily Trochoidea Rafinesque, 1815 (top shells) Superorder Neritaemorphi Koken, 1896 Order Cyrtoneritomorpha (fossil) Order Neritopsina Cox & Knight, 1960 Superfamily Neritoidea Lamarck, 1809 Superorder Caenogastropoda Cox, 1960 Order Architaenioglossa Haller, 1890 Superfamily Ampullarioidea J.E. Gray, 1824 Superfamily Cyclophoroidea J.E. Gray, 1847 (terrestrials) Order Sorbeoconcha Ponder & David R. Lindberg, 1997 Suborder Discopoda P. Fischer, 1884 Superfamily Campaniloidea Douvillé, 1904 Superfamily Cerithioidea Férussac, 1822 Suborder Hypsogastropoda Ponder & David R. Lindberg, 1997 Infraorder Littorinimorpha Golikov & Starobogatov, 1975 Superfamily Calyptraeoidea Lamarck, 1809 Superfamily Capuloidea J. Fleming, 1822 Superfamily Carinarioidea Blainville, 1818 (formerly called Heteropoda) Superfamily Cingulopsoidea Fretter & Patil, 1958 Superfamily Cypraeoidea Rafinesque, 1815 (cowries) Superfamily Ficoidea Meek, 1864 Superfamily Laubierinoidea Warén & Bouchet, 1990 Superfamily Littorinoidea (Children), 1834 (periwinkles) Superfamily Naticoidea Forbes, 1838 (moon shells) Superfamily Rissooidea J.E. Gray, 1847 (Risso shells) (includes genus Oncomelania, schistosomiasis transmission vector) Superfamily Stromboidea Rafinesque, 1815 (true conchs) Superfamily Tonnoidea Suter, 1913 Superfamily Trivioidea Troschel, 1863 Superfamily Vanikoroidea J.E. Gray, 1840 Superfamily Velutinoidea J.E. Gray, 1840 Superfamily Vermetoidea Rafinesque, 1815 (worm shells) Superfamily Xenophoroidea Troschel, 1852 (carrier shells) Infraorder Ptenoglossa J.E. Gray, 1853 Superfamily Eulimoidea Philippi, 1853 Superfamily Janthinoidea Lamarck, 1812 Superfamily Triphoroidea J.E. Gray, 1847 Infraorder Neogastropoda Thiele, 1929 Superfamily Buccinoidea (whelks, false tritions) Superfamily Cancellarioidea Forbes & Hanley, 1851 Superfamily Conoidea Rafinesque, 1815 Superfamily Muricoidea Rafinesque, 1815 Superorder Heterobranchia J.E. Gray, 1840 Order Heterostropha P. Fischer, 1885 Superfamily Architectonicoidea J.E. Gray, 1840 Superfamily Nerineoidea Zittel, 1873 (fossil) Superfamily Omalogyroidea G.O. Sars, 1878 Superfamily Pyramidelloidea J.E. Gray, 1840 Superfamily Rissoelloidea J.E. Gray, 1850 Superfamily Valvatoidea J.E. Gray, 1840 Order Opisthobranchia Milne-Edwards, 1848 Suborder Cephalaspidea P. Fischer, 1883 Superfamily Acteonoidea D'Orbigny, 1835 Superfamily Bulloidea Lamarck, 1801 Superfamily Cylindrobulloidea Thiele, 1931 (has to be included in the Sacoglossa) Superfamily Diaphanoidea Odhner, 1914 Superfamily Haminoeoidea Pilsbry, 1895 Superfamily Philinoidea J.E. Gray, 1850 Superfamily Ringiculoidea Philippi, 1853 Suborder Sacoglossa Von Ihering, 1876 Superfamily Oxynooidea H. Adams & A. Adams, 1854 Suborder Anaspidea P. Fischer, 1883 (sea hares) Superfamily Akeroidea Pilsbry, 1893 Superfamily Aplysioidea Lamarck, 1809 Suborder Notaspidea P. Fischer, 1883 Superfamily Tylodinoidea J.E. Gray, 1847 Superfamily Pleurobranchoidea Férussac, 1822 Suborder Thecosomata Blainville, 1824 (sea butterflies) Infraorder Euthecosomata Superfamily Limacinoidea Superfamily Cavolinioidea Infraorder Pseudothecosomata Superfamily Peraclidoidea Superfamily Cymbulioidea Suborder Gymnosomata Blainville, 1824 (sea angels) Family Clionidae Rafinesque, 1815 Family Cliopsidae Costa, 1873 Family Hydromylidae Pruvot-Fol, 1942 Family Laginiopsidae Pruvot-Fol, 1922 Family Notobranchaeidae Pelseneer, 1886 Family Pneumodermatidae Latreille, 1825 Family Thliptodontidae Kwietniewski, 1910 Suborder Nudibranchia Blainville, 1814 (nudibranchs) Infraorder Anthobranchia Férussac, 1819 Superfamily Doridoidea Rafinesque, 1815 Superfamily Doridoxoidea Bergh, 1900 Superfamily Onchidoridoidea Alder & Hancock, 1845 Superfamily Polyceroidea Alder & Hancock, 1845 Infraorder Cladobranchia Willan & Morton, 1984 Superfamily Dendronotoidea Allman, 1845 Superfamily Arminoidea Rafinesque, 1814 Superfamily Metarminoidea Odhner in Franc, 1968 Superfamily Aeolidioidea J.E. Gray, 1827
Order Pulmonata Cuvier in Blainville, 1814 (pulmonates) Suborder Systellommatophora Pilsbry, 1948 Superfamily Onchidioidea Rafinesque, 1815 Superfamily Otinoidea H. Adams & A. Adams, 1855 Superfamily Rathouisioidea Sarasin, 1889 Suborder Basommatophora Keferstein in Bronn, 1864 (freshwater pulmonates, pond snails) Superfamily Acroloxoidea Thiele, 1931 Superfamily Amphiboloidea J.E. Gray, 1840 Superfamily Chilinoidea H. Adams & A. Adams, 1855 Superfamily Glacidorboidea Ponder, 1986 Superfamily Lymnaeoidea Rafinesque, 1815 Superfamily Planorboidea Rafinesque, 1815 Superfamily Siphonarioidea J.E. Gray, 1840 Suborder Eupulmonata Haszprunar & Huber, 1990 Infraorder Acteophila Dall, 1885 (= formerly Archaeopulmonata) Superfamily Melampoidea Stimpson, 1851 Infraorder Trimusculiformes Minichev & Starobogatov, 1975 Superfamily Trimusculoidea Zilch, 1959 Infraorder Stylommatophora A. Schmidt, 1856 (land snails) Subinfraorder Orthurethra Superfamily Achatinelloidea Gulick, 1873 Superfamily Cochlicopoidea Pilsbry, 1900 Superfamily Partuloidea Pilsbry, 1900 Superfamily Pupilloidea Turton, 1831 Subinfraorder Sigmurethra Superfamily Acavoidea Pilsbry, 1895 Superfamily Achatinoidea Swainson, 1840 Superfamily Aillyoidea Baker, 1960 Superfamily Arionoidea J.E. Gray in Turnton, 1840 Superfamily Buliminoidea Clessin, 1879 Superfamily Camaenoidea Pilsbry, 1895 Superfamily Clausilioidea Mörch, 1864 Superfamily Dyakioidea Gude & Woodward, 1921 Superfamily Gastrodontoidea Tryon, 1866 Superfamily Helicoidea Rafinesque, 1815 Superfamily Helixarionoidea Bourguignat, 1877 Superfamily Limacoidea Rafinesque, 1815 Superfamily Oleacinoidea H. Adams & A. Adams, 1855 Superfamily Orthalicoidea Albers-Martens, 1860 Superfamily Plectopylidoidea Moellendorf, 1900 Superfamily Polygyroidea Pilsbry, 1894 Superfamily Punctoidea Morse, 1864 Superfamily Rhytidoidea Pilsbry, 1893 Superfamily Sagdidoidea Pilsbry, 1895 Superfamily Staffordioidea Thiele, 1931 Superfamily Streptaxoidea J.E. Gray, 1806 Superfamily Strophocheiloidea Thiele, 1926 Superfamily Trigonochlamydoidea Hese, 1882 Superfamily Zonitoidea Mörch, 1864 ? Superfamily Athoracophoroidea P. Fischer, 1883 (= Tracheopulmonata) ? Superfamily Succineoidea Beck, 1837 (= Heterurethra) Other extant classes of the Mollusca are Bivalvia, Scaphopoda, Aplacophora, Polyplacophora, Monoplacophora and Cephalopoda.
Bouchet & Rocroi, 2005 Philippe Bouchet and Jean-Pierre Rocroi published their revised taxonomy in 2005. The system encompasses both living and extinct groups, as well as some fossils whose classification as gastropods is uncertain. This taxnomy was laid out in a book-length paper entitled "Classification and Nomenclator of Gastropod Families", which was published in the journal Malacologia and which was written in collaboration with J. Frýda, B. Hausdorf, W. Ponder, Á. Valdés and A. Warén.
The Bouchet & Rocroi system was the first complete gastropod taxonomy that primarily employed the concept of clades, and was derived from research on molecular phylogenetics; in this context a clade is a "natural grouping" of organisms based upon a statistical cluster analysis. Higher taxa are expressed as unranked clades where known, and termed "informal groups" or groups" where monophyly (a single lineage) has not yet been determined, and where polyphyly (more than one lineage) is suspected. Clades are used between the rank of class and the rank of superfamily. The clades are unranked.