Decapod crustaceans from the Paleocene (Danian) of the Paris Basin (Vigny stratotype and allied localities) and a limpet palaeoassociation

摘要

As the lowermost stage of the Palaeogene, the Danian is a key period for ecosystems which followed the K-Pg boundary. The Vigny quarry (Val d'Oise, France) is a co-stratotype of the Danian stage, along with the well-known one of Fakse (Denmark). The Vigny ecosystem (Bois-des-Roches site at Vigny and allied Danian localities) is the only known Cenozoic reef of the Paris Basin and is formed by hermatypic corals, unlike reefs at Fakse. Well studied by scientists, including d'Orbigny, for almost two centuries, the decapod crustacean fauna of Vigny has been much less documented than that of Fakse. Here, we describe new material of decapod crustaceans from the Danian of the Paris Basin, based on material in the Museum national d'Histoire naturelle (Paris). This material (six carapaces and 14 isolated claws) constitutes anomurans, brachyurans and, for the first time, axiideans in the Danian of the Paris Basin. Among brachyurans, it includes the paleoxanthopsid crab Jakobsenius cretaceus is described and the dynomenid Dromiopsis mosae. Two new brachyuran species are described from Vigny: Titanocarcinus schweitzerae sp. nov. (Tumidocarcinidae) and Dromilites montenati sp. nov. (Dromiidae). The latter is the oldest representative of its genus. The Danian decapod crustaceans of the Paris Basin are revised and their diversity is compared to that at Fakse. The enigmatic association of a limpet (Patella herbetiana) attached to a crab carapace is described and interpreted. Based on a small number of available specimens, this study reveals some specificity of the Vigny brachyuran fauna and recognizes the Paris Basin as an important region for knowledge of Danian decapod crustaceans.