The Muschelkalk (German for "shell-bearing limestone"; French: calcaire coquillier) is a sequence of sedimentary rock strata (a lithostratigraphic unit) in the geology of central and western Europe.
The name indicates a characteristic feature of the unit, namely the frequent occurrence of lenticular banks composed of fossil shells.
The Muschelkalk is restricted to the subsurface in most of Germany and adjacent regions as the Low Countries, the North Sea and parts of Silesia, Poland and Denmark.
The Muschelkalk was deposited in a land-locked sea which, in the earlier part of its existence, had only imperfect communications with the more open waters of the Tethys Ocean to the south.
In Swabia and Franconia the highest beds are platy dolomites with Tringonodus sandergensis and the crustacean Bairdia.
In addition to the fossils mentioned above, the following are Muschelkalk forms: Coenothyris vulgaris, Mentzelia mentzeli and Spiriferina hirsuta, Myophoria vulgaris, Rhynchotites hirundo, Ceratites munsteri, Ptychites studeri, Balatonites balatonicus, Aspidura scutellata, Daonella lommeli, and in the Alpine region several rock-forming algae (for example, Baciryllium, Gyroporella, and Diplopora).