Pinna (bivalve) explained

Pinna is a genus of bivalve molluscs belonging to the family Pinnidae.[1]

The type species of the genus is Pinna rudis.

The most completely studied species in the genus is P. nobilis, a Mediterranean pen shell which was historically important as the principal source of sea silk.

Description

These pen shells can reach a length of about 80cm-90cmcm (30inches-40inchescm). They are characterized by thin, elongated, wedge-shaped, and almost triangular shells with long, toothless edges. The surface of the shells shows radial ribs over their entire length.

Pinna is distinguished from its sibling genus Atrina by the presence of a sulcus dividing the nacreous region of the valves, and the positioning of the adductor scar on the dorsal side of shells.

These bivalves most commonly lie point-first on the sea bottom in which they live, anchored by a net of byssus threads.

Distribution

Species in the genus Pinna are geographically widespread. This genus is very ancient, going back up to the Carboniferous period. It is especially represented in Jurassic and Cretaceous fossils.

Species

According to the World Register of Marine Species, species in the genus Pinna include:[2]

Nomen nudum

Nomen dubium

Synonyms

References

External links

Notes and References

  1. MolluscaBase eds. (2022). MolluscaBase. Pinna Linnaeus, 1758. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=138352 on 2022-01-16
  2. Book: http://www.marinespecies.org/aphia.php?p=taxdetails&id=138352 . Pinna Linnaeus, 1758 . WoRMS Editorial Board . Taxonomy . 2018 . World Register of Marine Species . 2018-12-31 . 10.14284/170 .
  3. Shilekhin . L. E. . Mazaev . A. V. . Biakov . A. S. . 2023 . The most ancient representatives of the genus Pinna (Bivalvia) in the Early Permian reef of Shakhtau (southern Cis-Urals, Russia) . Paleontological Journal . 57 . 4 . 21–25 . 10.1134/S0031030123040111 .