Pyramidelloidea is a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

of mostly very small sea snails, marine gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is es ...

s and

micromollusk A micromollusk is a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also ...

s within the clade

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. in October 2010. The older name "Pulmonata" referred to a group of gas ...

. This is a voluminous

taxon In biology, a taxon ( back-formation from '' taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular n ...

: above the species level close to 400 named taxa are referred to this gastropod superfamily. Pyramidelloidea has both

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

and recent members. They live as

ectoparasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

s on

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biv ...

molluscs and

polychaete Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ...

worms, and have a sharp, piercing stylet instead of a

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

Distribution

This taxon is found worldwide.

Taxonomy

1999 taxonomy

Taxonomy by Schander, Van Aartsen & Corgan (1999): *Superfamily Pyramidelloidea Gray, 1840 **Family Amathinidae Ponder, 1987 **Family Ebalidae Warén, 1994 - synonym: Anisocyclidae van Aartsen, 1995 **Family

Odostomiidae Odostomiinae, ''Odostomia'' snails and their allies, is a taxonomic subfamily of minute parasitic sea snails. These are marine heterobranch gastropod mollusks, or micromollusks, in the family Pyramidellidae. Taxonomy The subfamily Odostomi ...

Pelseneer, 1928 ***Subfamily

Odostomiinae Odostomiinae, ''Odostomia'' snails and their allies, is a taxonomic subfamily of minute parasitic sea snails. These are marine heterobranch gastropod mollusks, or micromollusks, in the family Pyramidellidae. Taxonomy The subfamily Odostomi ...

Pelseneer, 1928 ***Subfamily

Chrysallidinae Chrysallidinae is a taxonomic group of very small sea snails, marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies. Taxonomy Chrysallidinae has been one of eleven recognized subfamilies of the gastropod famil ...

Saurin, 1958 ***Subfamily

Odostomellinae Odostomellini is a taxonomic tribe of minute sea snails, marine gastropod molluscs within the family Pyramidellidae the pyrams and their allies. Taxonomy Odostomellinae has been one of eleven recognised subfamilies of the family Pyramidel ...

Saurin, 1958 ***Subfamily

Cyclostremellinae Cyclostremellini is a minor tribe, a taxonomic grouping, of minute sea snails, marine gastropod mollusks or micromollusks, in the family Pyramidellidae, the pyrams and their allies. Taxonomy Cyclostremellinae has been a subfamily one of el ...

Moore, 1966 **Family

Pyramidellidae Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs. The great majority of species of pyrams are micr ...

J. E. Gray, 1840 ***Subfamily

Pyramidellinae Pyramidellinae is a taxonomic subfamily of minute sea snails, marine gastropod mollusks in the family Pyramidellidae, the pyrams and their allies. MolluscaBase eds. (2021). MolluscaBase. Pyramidellinae. Accessed through: World Register of Ma ...

J.E. Gray, 1840 ***Subfamily Sayellinae Wise, 1996 **Family Syrnolidae Saurin, 1958 ***Subfamily Syrnolinae Saurin, 1958 ***Subfamily Tiberiinae Saurin, 1958 **Family Turbonillidae Bronn, 1849 ***Subfamily Turbonillinae Bronn, 1849 ***Subfamily

Eulimellinae Eulimellini is a tribe of minute sea snails, marine gastropod molluscs in the family Pyramidellidae, the pyrams and their allies. Taxonomy According to Schander, Van Aartsen & Corgan (1999) there are 17 genera in the Eulimellinae. As "Eu ...

Saurin, 1958 ***Subfamily

Cingulininae Cingulinini is a taxonomic tribe of very small sea snails, marine gastropod mollusks in the family Pyramidellidae, the pyrams and their allies. Taxonomy Cingulininae was first introduced by Saurin in 1959, and according to Schander, Van Aa ...

Saurin, 1959

2005 taxonomy

Pyramidelloidea has been classified within the informal group

Lower Heterobranchia Lower Heterobranchia, also known as the Allogastropoda, is a group of rather specialized, highly evolved sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatu ...

in the taxonomy of Bouchet & Rocroi (2005). Taxonomy of Bouchet & Rocroi, 2005: *Superfamily Pyramidelloidea **Family

**Family Amathinidae ** † Family

Heteroneritidae †Heteroneritidae is an extinct taxonomic family of sea snails, marine gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). Th ...

**Family Murchisonellidae

2010 taxonomy

Jörger et al. (2010) have redefined major groups within the Heterobranchia and they moved Pyramidelloidea to

.Jörger K. M., Stöger I., Kano Y., Fukuda H., Knebelsberger T. & Schrödl M. (2010). "On the origin of Acochlidia and other enigmatic euthyneuran gastropods, with implications for the systematics of Heterobranchia". ''

BMC Evolutionary Biology ''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology. It ...

'' 10: 323. .

Pyramidelloidean genera of uncertain familial position

* '' Bidentata'' de Castellanos, 1982 * '' Calyptopolyptychia'' Gougerot, 1968 * '' Laeviselica'' Gougerot & Le Renard, 1977 * '' Lysacme'' Dall & Bartsch, 1904 * '' Microthyca'' A. Adams, 1863 * '' Oopyramis'' Thiele, 1930 * '' Sulcorinella'' Dall & Bartsch, 1904

References

{{Taxonbar, from=Q141156 Panpulmonata Ectoparasites Marine gastropods Taxa named by John Edward Gray