Stylommatophora is an order of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon includes most land snails and slugs. The two strong synapomorphies of Stylommatophora are a long pedal gland placed beneath a membrane and two pairs of retractile tentacles (Dayrat & Tillier). Several families in this group contain species of snails and slugs that create love darts. Stylommatophora are known from the Cretaceous period up to the present day. 2005 taxonomy According to the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) based on evolutionary ancestry is the clade Stylommatophora in clade Eupulmonata within informal group Pulmonata. It uses unranked clades for taxa above the rank of superfamily (replacing the ranks suborder, order, superorder and subclass) and the traditional Linnaean approach for all taxa below the rank of superfamily. The clade Stylommatophora contains the subclades Elasmognatha, Orthurethra and the informal group Sigmurethra. The term "informal group" has been used to indicate whenever monophyly has not been tested, or where a traditional taxon of gastropods has now been discovered to be paraphyletic or polyphyletic. clade Elasmognatha Superfamily Succineoidea Superfamily Athoracophoroidea clade Orthurethra Superfamily Partuloidea Superfamily Achatinelloidea Superfamily Cochlicopoidea Superfamily Pupilloidea Superfamily Enoidea informal group Sigmurethra Superfamily Clausilioidea Superfamily Orthalicoidea Superfamily Achatinoidea Superfamily Aillyoidea Superfamily Testacelloidea Superfamily Papillodermatoidea Superfamily Streptaxoidea Superfamily Rhytidoidea Superfamily Acavoidea Superfamily Punctoidea Superfamily Sagdoidea "limacoid clade" (within the Sigmurethra) Superfamily Staffordioidea Superfamily Dyakioidea Superfamily Gastrodontoidea Superfamily Parmacelloidea Superfamily Zonitoidea Superfamily Helicarionoidea Superfamily Limacoidea (not in limacoid clade, but is within the Sigmurethra) Superfamily Arionoidea Superfamily Helicoidea Previous taxonomy 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. & 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 Sagdidoidera Pilsbry, 1895 Superfamily Staffordioidea Thiele, 1931 Superfamily Streptaxoidea J.E. Gray, 1806 Superfamily Strophocheiloidea Thiele, 1926 Superfamily Trigonochlamydoidea Hese, 1882 Superfamily Zonitoidea Mörch, 1864 References Extant Cretaceous first appearances