Aulacomya atra is native in South America - in Peru, Chile (where it grows up to 170 mm in length), the Falkland Islands and Argentina.

[2] It is also found on the coasts of New Zealand and southern Africa, from Namibia to Port Alfred, South Africa, from the intertidal to 40 m.[3] Introduced specimens have been found in Moray Firth, Scotland.

[2] In Southern Africa the species grows up to 90 mm in length.

It usually lives in crowded intertidal beds.

Individual animals have brown ribbed shells, which darken to black with age.