The mollusk shells from the Po Plain can be categorized into groups based on the depositional environment in which the species occurred. These distinct communities can be used to study the sequence stratigraphy of the Po Plain. One of these distinct groups of shells, or facies, is the beach ridge.

      The beach ridge includes the upper shoreface and lower shoreface. Some of the common mollusk species from the upper shoreface include the gastropod, Ovatella myosotis and the bivalve, Donax semistriatus. Some of the common species from the lower shoreface include the bivalves, Chamelea gallina and Thracia distorta. When these groups of shells, which tend to be from highly mobile taxa, are found in a sediment core from Po Plain, this is an indication of a beach ridge environment where that core was taken at the time that those shells occurred. The richness increases with water depth.

Here are representative images of these common beach ridge species, courtesy of Daniele Scarponi, University of Bologna, Italy.