Kingdom Animalia Phylum Mollusca | Class Gastropoda | |
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Similar Acteonoidea, Valvatoidea, Heterobranchia, Glacidorbidae, Amphiboloidea | ||
Lower Heterobranchia, also known as the Allogastropoda, is a group of rather specialized, highly evolved sea slugs and sea snails, (marine gastropod mollusks) within the clade Heterobranchia. Although the great majority of Lower Heterobranchs are indeed marine, a few have succeeded in making the transition to freshwater.
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Description
The shell shapes in this group are typically those that are seen in the sundial, pyramid, rissoella and orbitestellid families of snails.
2005 taxonomy
In the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005, the Lower Heterobranchia is an Informal Group. Superfamilies within the Lower Heterobranchia include:
(Taxa that are exclusively fossil are indicated with a dagger †)
For a more detailed taxonomy see: Taxonomy of the Gastropoda (Bouchet & Rocroi, 2005)#Informal group "Lower Heterobranchia" (= Allogastropoda)
2010 taxonomy
Jörger et al. (2010) have redefined major groups within the Heterobranchia: they moved Glacidorboidea and Pyramidelloidea to Panpulmonata.