Brachiopod biodiversity and characteristics from the Campanian Stratotype region (Les Charentes and Dordogne, France)

Abstract

With the purpose to reveal the Campanian heritage in the stratotype region, we took the opportunity to highlight, among the diverse fauna, the brachiopods: benthic marine invertebrates reported since the 19th century but never really detailed till now. The phylum Brachiopoda, present since the Cambrian, decreased in number of orders after the Permian-Triassic crisis with a replacement of taxa and another crisis after the Jurassic, but representatives are still present during the Cretaceous, even the Campanian till now. The limits of this stage were explicit since the mid 19th century for the basal part with the first occurrence of Rhynchonella globata, and the reports of several authors during the 20th century for the upper boundary. Noteworthy species (one Craniiformea and nearly twenty Rhynchonelliformea) are studied and positioned in a context with lithostratigraphic units, biozones, and six formations (Fm) named after different drillings. Using tomography to reveal the brachidium of some species was highly helpful. The environments in which lived the brachiopod species, from the lower to the upper Campanian, are evoked.