Description: Thallus horizontally flattened up to 20 cms across. Membranous when young, leathery and split when older. Margin with a hair-like fringe. Attached by rhizoids at the centre.

Habitat: Epilithic, sublittoral to 20 m.

Distribution: South-western distribution, found on the south coast of Ireland, Wales and south-west of England. Previous to 1975 the northern limit was the Channel Islands. Europe: Mediterranean including the Black Sea, Portugal, Atlantic coasts of Spain and France. Further afield: Morocco.

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

iNaturalist: Zanardinia prototypus at iNaturalist World Species Observations database.

WoRMS: Zanardinia prototypus at World Register of Marine Species.