Belemnites from the Upper Pliensbachian and the Toarcian (Lower Jurassic) of Tournadous (Causses, France)

Jurassic belemnites represent promising proxies especially for palaeoecological and also palaeobiogeographical reconstructions. However, basic knowledge on taxonomic composition, biostratigraphy and diversity of Early Jurassic belemnites is still dramatically low, especially for France. The present study provides new data on belemnites from the southern part of the Northwest European Province. More than 700 specimens have been collected along the Tournadous section in the Causses Basin (Southern France); they represent ten genera and 30 species belonging to Hastitidae, Megateuthididae, Passaloteuthididae, and Salpingoteuthididae. Furthermore, numerous ammonites have been collected, allowing to establish a standard chronostratigraphical scheme of the studied section and thus to assign, for the first time, a precise chronostratigraphical distribution to the Early Jurassic belemnites of Southern France. The analysis of belemnite diversity and its variations along the section compared to the well-known fauna of the northern part of the Northwest European province (Germany and England) open interesting prospective for belemnites palaeobiogeography.