Description: A solid shell which is almost circular and up to 6.5 cm in diameter. The are fine concentric lines and radiating ridges on the outer valve surface. Growth stages are clear in this species. It is dull brown to yellow in colour (often with a hint of red) which is either uniform, or may form zigzags on a white to cream background. The periostracum is dark brown and often covers the outer edge of each valve. Interior of shell is either white or very dark brown, especially at pallial line.

Habitat: Muddy, sandy or shelly gravel down to around 70 m.

Distribution: Found all around Britain and Ireland but seems more rare on North Sea coasts of Britain and Atlantic coasts of Ireland.

Similar Species: Unlikely to be confused with any other species.

Key Identification Features:

• Dull brown to yellow with hints of red.
• Uniform in colour or zigzag pattern.
• Periostracum forms dark brown band at outer edge of shell.

Distribution Map from NBN: Glycymeris glycymeris at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Glycymeris glycymeris at iNaturalist World Species Observations database.

GBIF data for Glycymeris glycymeris

WoRMS: Glycymeris glycymeris at World Register of Marine Species. Accepted name: Glycymeris glycymeris (Linnaeus, 1758). AphiaID: 140025.

Classification: Biota; Animalia; Mollusca; Bivalvia; Autobranchia; Pteriomorphia; Arcida; Arcoidea; Glycymerididae; Glycymeris