Gastropod taxonomy

thumb|Shells from a variety of prosobranch gastropods, from Ernst Haeckel's [[Artforms of Nature, 1904.]]

Caenogastropoda is a taxonomic subclass of molluscs in the class Gastropoda. It is 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 subclass is the most diverse and ecologically successful of the gastropods.

Heterobranchia, the heterobranchs (meaning "different gill"), is a taxonomic clade of snails and slugs, which includes marine, aquatic, and terrestrial gastropod molluscs.

The 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.

thumb|The fossil vetigastropod Discohelix tunisiensis from the Matmor Formation (Middle [[Jurassic) of southern Israel.]]

taxonomy published by Bouchet and Rocroi in 2005

Sigmurethra is a taxonomic category of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This is an informal group which includes most land snails and slugs.

Apogastropoda is a clade of gastropods uniting the highly diverse Caenogastropoda and Heterobranchia. Most caenogastropods are sea snails, whereas heterobranchs include not only sea snails but most species of sea slug, land snail, and land slug.

by Ponder & Lindberg, 1997

Euthecosomata is a taxonomic unit used to classify sea snails. It is a suborder of the order Pteropoda.

Cycloneritida (nerites and false-limpets) is an order of land snails, freshwater snails, and sea snails.