Basommatophora
Encyclopedia
Basommatophora was a term that was previously used as a taxonomic informal group, a group of snail
s within the informal group Pulmonata
, the air-breathing slugs and snails. 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" was used.
Basommatophora are known from the Carboniferous
to the recent periods.
Most of the families in this suborder are air-breathing freshwater snails. The three most abundant families in terms of number of species are, the Lymnaeidae (pond snails), the Planorbidae (ramshorn snails) and the Physidae (pouch or bubble snails). These are found in ponds, creeks, ditches, and shallow lakes nearly worldwide.
The Siphonariidae
on the other hand are unusual in that they have secondarily returned to the sea, and are now sea snails, limpet
-like marine
gastropods which live in the rocky intertidal zone
but which still breathe air and become active at low tide. 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 semi-terrestrial. Members of the family Chilinidae are confined to temperate parts of South America, and the Latiidae are limpet-like and confined to New Zealand.
Basommatophorans are characterized by having their eyes located at the base of their non-retractile tentacles, rather than at the tips, as in the true land snails Stylommatophora
. The majority of basommatophorans have shells that are thin, translucent, and relatively colorless, and all except Amphibola lack an operculum
.
the suborder Basommatophora consisted of the families :
Hygrophila
(according to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
):
Clade Hygrophila
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.
, superfamily Amphiboloidea
, and clade Hygrophila
) into a new taxon, Panpulmonata
.
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s within the informal group Pulmonata
Pulmonata
The Pulmonata, or "pulmonates", are an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills...
, the air-breathing slugs and snails. According to the taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
, whenever monophyly
Monophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
has not been tested, or where a traditional taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
of gastropods has now been discovered to be paraphyletic or polyphyletic, the term "group" or "informal group" was used.
Basommatophora are known from the Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
to the recent periods.
Most of the families in this suborder are air-breathing freshwater snails. The three most abundant families in terms of number of species are, the Lymnaeidae (pond snails), the Planorbidae (ramshorn snails) and the Physidae (pouch or bubble snails). These are found in ponds, creeks, ditches, and shallow lakes nearly worldwide.
The Siphonariidae
Siphonariidae
Siphonariidae is a taxonomic family of small to medium-sized air-breathing sea snails, marine and brackish water pulmonate gastropod molluscs. These snails are sometimes known as "false limpets" because of the shape of the shell, but they are not at all closely related to true limpets...
on the other hand are unusual in that they have secondarily returned to the sea, and are now sea snails, limpet
Limpet
Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...
-like marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
gastropods which live in the rocky intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
but which still breathe air and become active at low tide. The single species in the family Amphibolidae
Amphibolidae
Amphibolidae is a family of air-breathing snails with opercula, terrestrial pulmonate gastropod molluscs.The family is considered to be among the most primitive of the pulmonate gastropods, for although amphibolids breathe air, they also have opercula and at least some species go through a...
is archaic and retains an operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
. It lives at such a high tidal level that it could perhaps be considered semi-terrestrial. Members of the family Chilinidae are confined to temperate parts of South America, and the Latiidae are limpet-like and confined to New Zealand.
Basommatophorans are characterized by having their eyes located at the base of their non-retractile tentacles, rather than at the tips, as in the true land snails Stylommatophora
Stylommatophora
Stylommatophora is a taxon of air-breathing land snails and slugs, terrestrial pulmonate gastropod molluscs. This taxon is currently considered to be a clade. It was previously regarded as an infraorder...
. The majority of basommatophorans have shells that are thin, translucent, and relatively colorless, and all except Amphibola lack an operculum
Operculum (gastropod)
The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...
.
1997 taxonomy
In the older taxonomy of the Gastropoda (Ponder & Lindberg, 1997)Taxonomy of the Gastropoda (Ponder & Lindberg, 1997)
The taxonomy of the Gastropoda, as revised by Winston Ponder and David R. Lindberg in 1997, is an older taxonomy of the class Gastropoda, the class of molluscs consisting of all snails and slugs...
the suborder Basommatophora consisted of the families :
- AcroloxidaeAcroloxidaeAcroloxidae, commonly known as river limpets, are a taxonomic family of very small, freshwater snails, aquatic pulmonate gastropod limpet-like mollusks with a simple flattened conical shell in the clade Hygrophila....
Thiele, 1931 - AmphibolidaeAmphibolidaeAmphibolidae is a family of air-breathing snails with opercula, terrestrial pulmonate gastropod molluscs.The family is considered to be among the most primitive of the pulmonate gastropods, for although amphibolids breathe air, they also have opercula and at least some species go through a...
J. E. Gray, 1840 - only one species Amphibola crenataAmphibola crenataAmphibola crenata is a species of air breathing snail with an operculum, a pulmonate gastropod mollusc which lives in a habitat that is intermediate between the land and the sea, not entirely terrestrial and not entirely marine... - AncylidaeAncylidaeAncylini is a tribe of small, freshwater, air-breathing limpets, aquatic pulmonate gastropod mollusks in the family Planorbidae the ram's horn snails and their allies...
- CarychiidaeCarychiidaeCarychiinae is a taxonomic subfamily of minute air-breathing land snails, terrestrial pulmonate gastropod mollusks.This subfamily is part of the family Ellobiidae, in the clade Eupulmonata.-Genera:Genera within the subfamily Carychiinae include:...
Jeffreys, 1830 - Chilinidae
- Lancidae
- Latiidae
- LymnaeidaeLymnaeidaeLymnaeidae is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila....
Rafinesque, 1815 - Otinidae H. Adams & A. Adams, 1855
- PhysidaePhysidaePhysidae, common name bladder snails, are a monophyletic taxonomic family of small freshwater snails, aquatic pulmonate gastropod molluscs in the clade Hygrophila....
Fitzinger, 1833 - PlanorbidaePlanorbidaePlanorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks....
Rafinesque, 1815 - SiphonariidaeSiphonariidaeSiphonariidae is a taxonomic family of small to medium-sized air-breathing sea snails, marine and brackish water pulmonate gastropod molluscs. These snails are sometimes known as "false limpets" because of the shape of the shell, but they are not at all closely related to true limpets...
J. E. Gray, 1840 - TrimusculidaeTrimusculidaeTrimusculus is a genus of medium-sized air-breathing sea snails or false limpets, marine pulmonate gastropod molluscs.Trimusculus is the only genus in the family Trimusculidae...
Zilch, 1959
2005 taxonomy
The informal group Basommatophora contains the following superfamilies and the cladeClade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Hygrophila
Hygrophila (clade)
Hygrophila is a taxonomic clade of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks within the clade Panpulmonata.The families in this clade are basically air-breathing freshwater snails including freshwater limpets...
(according to the Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised by Philippe Bouchet and Jean-Pierre Rocroi is currently the most up-to-date overall system for classifying gastropod mollusks...
):
- Superfamily AmphiboloideaAmphiboloideaAmphiboloidea is a taxonomic superfamily of air-breathing land snails.- 2005 taxonomy :According to the taxonomy of the Gastropoda , it is a superfamily in the informal group Basommatophora, within the Pulmonata....
Gray, 1840- Family AmphibolidaeAmphibolidaeAmphibolidae is a family of air-breathing snails with opercula, terrestrial pulmonate gastropod molluscs.The family is considered to be among the most primitive of the pulmonate gastropods, for although amphibolids breathe air, they also have opercula and at least some species go through a...
Gray, 1840
- Family Amphibolidae
- Superfamily SiphonarioideaSiphonarioideaSiphonarioidea is a taxonomic group of air-breathing sea snails or false limpets.- 2005 taxonomy :Siphonarioidea was previously a superfamily in the informal group Basommatophora within the Pulmonata.- 2010 taxonomy :...
Gray, 1827- Family SiphonariidaeSiphonariidaeSiphonariidae is a taxonomic family of small to medium-sized air-breathing sea snails, marine and brackish water pulmonate gastropod molluscs. These snails are sometimes known as "false limpets" because of the shape of the shell, but they are not at all closely related to true limpets...
Gray, 1827 - † Family AcroreiidaeAcroreiidae† Acroreiidae is an extinct family of air-breathing snails, pulmonate gastropod mollusks in the superfamily Siphonariidae. The living siphonariids are all marine pulmonates, false sea limpets that breathe air.- Taxonomy :...
Cossmann, 1893
- Family Siphonariidae
Clade Hygrophila
Hygrophila (clade)
Hygrophila is a taxonomic clade of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks within the clade Panpulmonata.The families in this clade are basically air-breathing freshwater snails including freshwater limpets...
- Superfamily ChilinoideaChilinoideaChilinoidea is a superfamily of air-breathing freshwater snails, pulmonate gastropod mollusks in the clade Hygrophila....
Dall, 1870- Family Chilinidae Dall, 1870
- Family Latiidae Hutton, 1882
- Superfamily Acroloxoidea Thiele, 1931
- Family AcroloxidaeAcroloxidaeAcroloxidae, commonly known as river limpets, are a taxonomic family of very small, freshwater snails, aquatic pulmonate gastropod limpet-like mollusks with a simple flattened conical shell in the clade Hygrophila....
Thiele, 1931
- Family Acroloxidae
- Superfamily Lymnaeoidea Rafinesque, 1815
- Family LymnaeidaeLymnaeidaeLymnaeidae is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila....
Rafinesque, 1815
- Family Lymnaeidae
- Superfamily PlanorboideaPlanorboideaPlanorboidea is a superfamily of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks.The gastropods in this superfamily are all sinistral in shell coiling.The monophyly of Planorboidea has been confirmed by Albrecht et al. ....
Rafinesque, 1815- Family PlanorbidaePlanorbidaePlanorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks....
Rafinesque, 1815 - Family PhysidaePhysidaePhysidae, common name bladder snails, are a monophyletic taxonomic family of small freshwater snails, aquatic pulmonate gastropod molluscs in the clade Hygrophila....
Fitzinger, 1833
- Family Planorbidae
The family Ancylidae
Ancylidae
Ancylini is a tribe of small, freshwater, air-breathing limpets, aquatic pulmonate gastropod mollusks in the family Planorbidae the ram's horn snails and their allies...
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
Planorbidae
Planorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks....
Rafinesque, 1815.
The family Carychiidae
Carychiidae
Carychiinae is a taxonomic subfamily of minute air-breathing land snails, terrestrial pulmonate gastropod mollusks.This subfamily is part of the family Ellobiidae, in the clade Eupulmonata.-Genera:Genera within the subfamily Carychiinae include:...
has been reduced in this taxonomy to the status of subfamily Carychiinae Jeffreys, 1830 of the family Ellobiidae
Ellobiidae
Ellobiidae is a family of small air-breathing land snails, terrestrial pulmonate gastropod mollusks in the clade Eupulmonata. This is the only family in the superfamily Ellobioidea, according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005)....
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
Lymnaeidae
Lymnaeidae is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila....
Rafinesque, 1815.
2010 taxonomy
More recently, the Basommatophora was been found to be polyphyletic, and so Jörger et al. (2010) moved its three members, the (superfamily SiphonarioideaSiphonarioidea
Siphonarioidea is a taxonomic group of air-breathing sea snails or false limpets.- 2005 taxonomy :Siphonarioidea was previously a superfamily in the informal group Basommatophora within the Pulmonata.- 2010 taxonomy :...
, superfamily Amphiboloidea
Amphiboloidea
Amphiboloidea is a taxonomic superfamily of air-breathing land snails.- 2005 taxonomy :According to the taxonomy of the Gastropoda , it is a superfamily in the informal group Basommatophora, within the Pulmonata....
, and clade Hygrophila
Hygrophila
Hygrophila, commonly known as the temple plants or hygros, is a genus of flowering plants in the family Acanthaceae. There are about 125 species, of which about 40 are aquatic. The genus has a pan-tropical distribution, with some members entering sub-tropical areas. It is one of only two genera in...
) into a new taxon, Panpulmonata
Panpulmonata
Panpulmonata is a taxonomic clade of snails and slugs in the clade Heterobranchia within the clade Euthyneura.Panpulmonata was established as a new taxon by Jörger et al...
.