Fossil specimens of Neopycnodonte species possibly dating as old as about 60 million years (Paleocene).

[4][5] 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.

[6][7] 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.[8][9] Species within the genus Neopycnodonte include:[2]