Phosphatized adductor muscle remains in a Cenomanian limid bivalve from Villers-sur-Mer (France)

Soft-tissue preservation in molluscs is generally rare, particularly in bivalves and gastropods. Here, we report a three-dimensionally preserved specimen of the limid Acesta clypeiformis from the Cenomanian of France that shows preservation of organic structures of the adductor muscles. Examination under UV-light revealed likely phosphatisation of organic remains, which was corroborated by EDX-analyses. We suggest that the parts of the adductor muscles that are very close to the attachment are particularly resistant to decay and thus may be preserved even under taphonomic conditions usually not favouring soft-tissue fossilisation.