Basommatophora

Taxobox
name = Basommatophora
fossil_range= fossil range|Carboniferous|recent


image_caption = "The larger of the two basommatophoran snails shown here is Lymnaea stagnalis"
regnum = Animalia
phylum = Mollusca
classis = Gastropoda
subclassis = Orthogastropoda
superordo = Heterobranchia
ordo = Pulmonata
subordo = Basommatophora
subordo_authority = Keferstein in Bronn, 1864
subdivision_ranks = Families
subdivision = See text.

"Basommatophora" is a taxonomic informal group within the informal group Pulmonata. According to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005), whenever monophyly has not been tested, or where a traditional taxon of gastropods has now been discovered to be paraphyletic or polyphyletic, the term "group" or "informal group" has been used.

Basommatophora are known from the Carboniferous to the recent periods. [(in Czech) Pek I., Vašíček Z., Roček Z., Hajn. V. & Mikuláš R.: "Základy zoopaleontologie". - Olomouc, 1996. 264 pp., ISBN 80-7067-599-3.]

Most of the families in this suborder are air-breathing freshwater snails, but the Siphonariidae are unusual in that they have secondarily returned to the sea, and are now marine gastropods. The single species in the family Amphibolidae is archaic and retains an operculum. It lives at such a high tidal level that it could perhaps be considered terrestrial.

Taxonomy

The informal group Basommatophora contains the following superfamilies and the clade Hygrophila
*Superfamily Amphiboloidea Gray, 1840
**Family Amphibolidae Gray, 1840
*Superfamily Siphonarioidea Gray, 1827
**Family Siphonariidae Gray, 1827
** † Family Acroreiidae Cossmann, 1893

Clade Hygrophila

*Superfamily Chilinoidea Dall, 1870
**Family Chilinidae Dall, 1870
**Family Latiidae Hutton, 1882
*Superfamily Acroloxoidea Thiele, 1931
**Family Acroloxidae Thiele, 1931
*Superfamily Lymnaeoidea Rafinesque, 1815
**Family Lymnaeidae Rafinesque, 1815
*Superfamily Planorboidea Rafinesque, 1815
**Family Planorbidae Rafinesque, 1815
**Family Physidae Fitzinger, 1833

In the older taxonomy the suborder Basommatophora consisted of the families :

* Acroloxidae Thiele, 1931
* Amphibolidae J. E. Gray, 1840 - only one species "Amphibola crenata"
* Ancylidae
* Carychiidae Jeffreys, 1830
* Chilinidae
* Lancidae
* Latiidae
* Lymnaeidae Rafinesque, 1815
* Otinidae H. Adams & A. Adams, 1855
* Physidae Fitzinger, 1833
* Planorbidae Rafinesque, 1815
* Siphonariidae J. E. Gray, 1840
* Trimusculidae Zilch, 1959

The family Ancylidae has been reduced in the new taxonomy to the status of tribe Ancylini Rafinesque, 1815 of the subfamily Planorbinae Rafinesque, 1815 of the family Planorbidae Rafinesque, 1815

The family Carychiidae has been reduced in this taxonomy to the status of subfamily Carychiinae Jeffreys, 1830 of the family Ellobiidae L. Pfeiffer, 1854 (1822)

The family Lancidae has been reduced in this taxonomy to the status of subfamily Lancinae Hannibal, 1814 of the family Lymnaeidae Rafinesque, 1815 .

References