Atrina is a cosmopolitan genus of bivalve molluscs belonging to the family Pinnidae.

A typical species is A. fragilis, found in British waters. A. rigida (Lightfoot, 1786) is found on the southeast coast of North America and in the West Indies. The type species is A. nigra (Dillwyn, 1817, originally P. nigra).

Atrina is considered to represent the more primitive form within the Pinnidae; however, both genera Pinna and Atrina are very ancient. The genus Atrina is represented within the fossil record from the Triassic period to the Quaternary period (age range: 242.0 to 0.0 million years ago). These fossils have been found all over the world.

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