Freshwater Bivalves - Coquina
Bivalvia, Mittelmiozän
About the object
Alongside innumerable plant fossils, fossils of freshwater bivalves were also found preserved in the marlstone inside the Bohlinger Schlucht. Coquina is a rock sediment formed by the aggregation of empty shells from molluscs, brachiopods, crustaceans, sea urchins and other shell-bearing animals. These fossilised freshwater bivalves inhabited the rivers, lakes and marshlands comprising the freshwater ecosystem found in the northern Alpine foothills 13.5 million years ago. They lived at the bottom of the water and fed on organic material that they filtered out of the sediment. The shells of the mussels are composed of aragonite, a form of calcium carbonate. During the fossil preparation, attention was primarily given to the plant fossil finds taken from the Bohlinger Schlucht, whereby the broken pieces of bivalve mussel scattered about were removed.