Rogueus belgodereae, a new raninoid crab (Crustacea: Brachyura: Raninoidea) from the Upper Palaeocene (Thanetian) of Southern France, with comments on early palaeocene decapod crustacean faunules

Abstract

Palaeocene crabs are rare globally; crab faunules of this period are mostly described from reefal environments, and little is reported about non-reefal environments. A new raninoid crab is described and formally named from Thanetian (upper Palaeocene) non-reefal deeper water deposits of Boussens, southern France. The new species is assigned to the genus Rogueus, from which only two species were previously known, and this new record suggests the genus was widespread in the European Palaeocene. A rich Palaeocene brachyuran assemblage of this locality is preliminarily presented and briefly discussed. It appears that eubrachyuran crabs dominated this palaeoenvironment. Based on the global fossil record, it appears that brachyuran crabs quickly recovered after the K/Pg extinction event and were able to restock both reefal and non-reefal environments, prior to the explosive diversification of decapods during the Early Eocene Climatic Optimum.