Heterobranchia Temporal range: | |
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Four examples of Heterobranchia | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Heterobranchia J.E. Gray, 1840 |
Taxonomic subcategories | |
informal group Lower Heterobranchia Contents |
Heterobranchia, the heterobranchs (meaning "different-gilled snails"), is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks.
Heterobranchia is one of the main clades of gastropods. Currently Heterobranchia comprises three informal groups: the lower heterobranchs, the opisthobranchs and the pulmonates. [2]
This section needs to be updated. The reason given is: This section uses long abandoned groups, refuted by molecular phylogenetics..(August 2023) |
The three subdivisions of this large clade are quite diverse:
The families currently included in Heterobranchia have historically been placed in many different parts of the taxonomic class of gastropods. Earlier authors (such as J.E. Gray, 1840) considered Heterobranchia to consist of only marine gastropods, and conceptualized it as a borderline category, intermediate between the Opisthobranchia & Pulmonata, and all the other gastropods. [7]
The (sometimes recognized) category Heterostropha within the Heterobranchia, which includes such families as Architectonicidae, the sundial or staircase snails, is primarily characterized by a shell which has a heterostrophic protoconch, in other words the apical whorls are coiled in the opposite plane to the adult whorls. The classification of this group was revised by Ponder & Warén in 1988. [8]
According to the older taxonomy of the Gastropoda (Ponder & Lindberg, 1997) the Heterobranchia were ranked as a superorder.
Heterobranchia is currently one of the main clades of gastropods. For a detailed taxonomy, see Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)#Clade Heterobranchia.
Jörger et al. (2010) [9] have redefined major groups within the Heterobranchia: they created the new clades Euopisthobranchia and Panpulmonata. [9]
A cladogram showing phylogenic relations of Heterobranchia as proposed by Jörger et al. (2010): [9]
Heterobranchia |
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Opisthobranchs is a now informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping.
Acteonoidea is a superfamily of sea snails, or bubble snails, marine gastropod mollusks.
Pulmonata or pulmonates, is 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 group includes many land and freshwater families, and several marine families.
Basommatophora was a term that was previously used as a taxonomic informal group, a group of snails within the informal group Pulmonata, the air-breathing slugs and snails. According to the taxonomy of the Gastropoda, 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.
Amphibolidae is a family of air-breathing snails with opercula, terrestrial pulmonate gastropod molluscs.
Pyramidelloidea is a superfamily of mostly very small sea snails, marine gastropod mollusks and micromollusks within the clade Panpulmonata.
Amphiboloidea is a taxonomic superfamily of air-breathing land snails.
Euthyneura is a taxonomic infraclass of snails and slugs, which includes species exclusively from marine, aquatic and terrestrial gastropod mollusks in the clade Heterobranchia.
Lower Heterobranchia, also known as the Allogastropoda, is a group of rather specialized, highly evolved sea slugs and sea snails, within the subclass Heterobranchia.
Nudipleura are a clade of sea snails and sea slugs, marine gastropod mollusks within the large clade Heterobranchia.
Acochlidiacea, common name acochlidians, are a taxonomic clade of very unusual sea snails and sea and freshwater slugs, aquatic gastropod mollusks within the large clade Heterobranchia. Acochlidia is a variant spelling.
Runcinoidea is a taxonomic superfamily or a clade Runcinaecea of sea slugs, marine gastropod mollusks in the order Runcinida
Strubellia paradoxa is a species of freshwater slug, a shell-less freshwater gastropod, an aquatic gastropod mollusk within the clade Acochlidiacea.
The Glacidorbidae is a taxonomic family of freshwater snails.
†Heteroneritidae is an extinct taxonomic family of sea snails, marine gastropod mollusks in the superfamilia Pyramidelloidea.
Hygrophila is a taxonomic superorder of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks within the clade Panpulmonata.
This overview lists proposed changes in the taxonomy of gastropods at the family level and above since 2005, when the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) was published. In other words, these are recent updates in the way various groups of snails and slugs are classified.
Panpulmonata is a taxonomic clade of snails and slugs in the clade Heterobranchia within the clade Euthyneura.
Euopisthobranchia is a taxonomic clade of snails and slugs in the clade Heterobranchia within the clade Euthyneura.
Architectibranchia is a clade of marine snails, gastropod molluscs.