Article: The recognition of salinity-controlled mollusc assemblages in the Great Estuarine Series (Middle Jurassic) of the Inner Hebrides

The Great Estuarine Series was deposited in large, shallow lagoons. Its abundant molluscan faunas are restricted to very few genera and species, several of which are similar to modern fresh- and brackish-water forms. Consideration of the nature and history of the brackish-water fauna, together with direct comparison with the modern brackish-water environments of the Texas coast, results in an interpretation of the faunas as being controlled very largely by salinity variations in time. The salinities ranged from freshwater to fully marine, but were usually intermediate.