''Neopycnodonte'' is a genus of marine

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Gryphaeidae The Gryphaeidae, common name the foam oysters or honeycomb oysters, are a family of marine bivalve mollusks. This family of bivalves is very well represented in the fossil record, however the number of living species is very few. All species ...

. This genus is very well represented in the

fossil record 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 ...

, however the number of living species is very few. Fossil specimens of ''Neopycnodonte'' species possibly dating as old as about 60 million years (

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

). Extant species have been recorded as fossils from the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

to the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

(from 20.43 to 0.012 Ma).

Description

This genus includes deep-sea giant oysters with shells measuring up to 30 cm. The shells are usually brittle, inequivalve, with a left convex valve cemented to a substrate, while the right non-cemented one is flat or slightly concave. These bivalves can live for several centuries.

Distribution and habitat

While about 25 million years these mollusks formed large colonies near the coast, for unknown reasons they migrated to deeper waters. They usually live in the Mediterranean canyons or along the continental margins at depths of 350 m to 750 m.Marine Bivalve Shells of the British Isles
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Species

Species within the genus ''Neopycnodonte'' include:WoRMS
/ref> * '' Neopycnodonte cochlear'' (Poli, 1795) * †'' Neopycnodonta navicularis'' Brocchi 1814 ''N. navicularis'' at Fossilworks
/ref> * '' Neopycnodonte zibrowii'' Gofas, Salas & Taviani, 2009

References

Gryphaeidae Extant Miocene first appearances Bivalve genera {{bivalve-stub