Ostrea edulis

[3] The fossil record of this species dates back to the Miocene (age range: 15.97 million years ago to present day).

Fossils have been found in Belgium, Italy, the Netherlands, Egypt, Greece, Spain, the United Kingdom, Austria, France and Germany.

[5] Shells are oval or pear shaped, white, yellowish or cream in colour, with a rough outer surface showing pale brown or bluish concentric bands on the right valve.

[8] Naturally viable populations have appeared in eastern North America from Maine to Rhode Island subsequent to artificial introduction in the 1940s and 1950s.

[12] In the 1950s, Dutch scientists artificially introduced Belon oyster seed into the waters around Maine in hopes to establish a viable stock.

The species once dominated European oyster production but disease, pollution, and overfishing sharply reduced the harvest.

[14][15] The adductor muscle of the European flat in combination with the shape of the shell results in a somewhat weaker seal compared with other oyster species.

Fossil of Ostrea edulis from Pliocene of Italy
Ostrea edulis ; a) labial palpi b) gills c) mantle d) junction of the two folds of the mantle e) large adductor muscle f) the shell
Worldwide O. edulis harvest in tonnes, 1950–2003
Loch Ryan oysters are sourced from Scotland's only commercial European flat oyster bed.