Pyramidellidae

Pyramidellidae
Live Turbonilla acutissima
Apertural view of a shell of Pyramidella acus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Pyramidelloidea
Family: Pyramidellidae
J. E. Gray, 1840[1]
Type genus
Pyramidella
Lamarck, 1799
Synonyms
  • Chemnitziidae
  • Heterostropha

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 micromolluscs.

The pyram family is distributed worldwide with more than 6,000 named species in more than 350 nominal genera and subgenera.[2]

This family of micromolluscs has been little studied and the phylogenetic relationships within the family are not well worked out. There is an absence of a general consensus regarding which species belong to a specific genus or subgenus, contributing to much confusion. Schander (1999) names more than 300 supraspecific names.[3] As there has been no serious generic revision of the genera worldwide, generic polyphyly can be expected to be rampant throughout the family. However, the family itself is deemed monophyletic.[4] However a study in 2011 seems to indicate that this family is deeply nested within the Pulmonata instead of the Heterobranchia.[5]

The family is currently divided into 11 subfamilies (Ponder & Lindberg 1997).[6] An alternative interpretation is that the family Pyramidellidae is but one of six families within the superfamily Pyramidelloidea (Schander, van Aartsen & Corgan 1999).[7] Many species are rare or infrequently recorded.

  1. ^ Gray, J. E. (1840). Synopsis of the contents of the British Museum, 42nd edition. London. p. 370 pp.
  2. ^ Schander, Christoffer; Halanych, Kenneth M.; Dahlgren, Thomas; Sundberg, Per (2003). "Test of the monophyly of Odostomiinae and Turbonilliinae (Gastropoda, Heterobranchia, Pyramidellidae) based on 16S mtDNA sequences". Zoologica Scripta. 32 (3): 243–254. doi:10.1046/j.1463-6409.2003.00112.x. S2CID 84249963.
  3. ^ Schander, Christoffer; Hori, Shigeo; Lundberg, Joakim (2011). "Anatomy, phylogeny and biology of Odostomella and Herviera, with the description of a new species of Odostomella (Mollusca, Heterostropha, Pyramidellidae)". Ophelia. 51 (1): 39–76. doi:10.1080/00785326.1999.10409399.
  4. ^ Dinapoli, A.; Zinssmeister, C.; Klussmann-Kolb, A. (2010). "New insights into the phylogeny of the Pyramidellidae (Gastropoda)". Journal of Molluscan Studies. 77 (1): 1–7. doi:10.1093/mollus/eyq027.
  5. ^ Dinapoli A, Zinssmeister C, Klussman-Kolb A. 2011. New insights into the phylogeny of the Pyramidellidae (Gastropoda). Journal of Molluscan Studies 77:1-7.
  6. ^ Cite error: The named reference Ponder was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Schander1999 was invoked but never defined (see the help page).