An identification key for dermal denticles of Rajidae from the North Sea

As a result of more systematic fine sieving on archaeological sites, dermal denticles and isolated teeth of rays are now more frequently recovered than before. A detailed description of the teeth is available in the literature, but no comparative study of the morphology of the dermal denticles exists that allows the identification of such elements issued from archaeological sites. A key and illustrations are provided for the identification of the dermal denticles of 10 ray species from the North Sea. In addition, the ray denticles have been analysed from seven medieval and postmedieval sites showing their potential for the interpretation of ichthyo-archaeological assemblages.