WApogastropoda was previously used as a major taxonomic grouping of sea snails, marine gastropod molluscs. This infraclass mostly consisted of marine limpets and operculate snails. At least 20,000 species were considered to exist within the two clades that were included, Heterobranchia and Caenogastropoda.
WCaenogastropoda is a taxonomic clade, a large diverse group which are mostly sea snails and other marine gastropod mollusks, but also includes some freshwater snails and some land snails. The clade is the most diverse and ecologically successful of the gastropods.
WCycloneritida is a order of land snails, freshwater snails, and sea snails.
WHeterobranchia, the heterobranchs, is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks.
WThe Patellogastropoda, common name true limpets and historically called the Docoglossa, are members of a major phylogenetic group of marine gastropods, treated by experts either as a clade or as a taxonomic order.
WProsobranchia was a large taxonomic subclass of sea snails, land snails and freshwater snails. This taxon of gastropods dates back to the 1920s. It has however been proven to be polyphyletic. Generally speaking in biology taxonomy is required to reflect phylogeny, in other words the classification of a group must reflect its evolutionary descent, as far as that is known, so the taxon Prosobranchia is no longer considered suitable to be used.
WSigmurethra is a taxonomic category of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This is an informal group which includes the majority of land snails and slugs.
WThe taxonomy of the cone snails and their allies as proposed by John K. Tucker and Manuel J. Tenorio in 2009 was a biological classification system for a large group of predatory sea snails. This system was an attempt to make taxonomic sense of the large and diverse group which contains the family Conidae, the cone snails. The authors proposed extensive changes to the family Conidae in contrast to the way the group was treated in the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005. Bouchet and Rocroi included in the family Conidae several other groups of toxoglossan snails which had previously been placed in the Turridae.
WVetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetigastropoda are sometimes treated as an order, although they are treated as an unranked clade in Bouchet and Rocroi, 2005.