Stylommatophora

Stylommatophora Temporal range: Cretaceous–Recent PreЄ Є O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Heterobranchia clade Euthyneura clade Panpulmonata clade Eupulmonata clade Stylommatophora A. Schmidt, 1855
Subdivision ranks
clade Elasmognatha clade Orthurethra informal group Sigmurethra
Diversity
about 20,500 species

Helix aspersa (Common Garden Snail)

Stylommatophora is a taxon of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon is considered to be a clade. It used to be regarded as an infraorder (also sometimes was considered to be an order). This taxon includes the majority of 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 to the Recent periods.

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
  

  Cepaea hortensis, within the Helicoidea.
  

  An individual of Trochulus hispidus, a stylommatophoran land snail in the family Hygromiidae within the Helicoidea.
• 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