A rich coprolite assemblage from Angeac-Charente (France): A glimpse into trophic interactions within an Early Cretaceous freshwater swamp

Abstract

Coprolites (fossil droppings) are common in the Mesozoic fossil record. However, coprolite assemblages from continental settings have more rarely been quantitatively analysed than the marine ones. The excavation of the Berriasian continental Lagerstätte of Angeac-Charente (France) during the last decade has resulted in unearthing a vast number of fossils, including ca. 6000 coprolite specimens. This large collection, accompanied by spatially landmarked depositional data, offers a unique opportunity to assess the organism interactions in an Early Cretaceous freshwater swamp ecosystem. We assign the coprolites to nine morphotypes based on their morphology and contents (using tomography and thin-sections), and to four taphonomic categories. We compare the specimens to other fossil and recent droppings, including newly imaged crocodilian faeces. While the Angeac-Charente biota comprised animals of a range of different ecologies, including waters primary inhabitants (chelonians, crocodylomorphs, actinopterygians) and a variety of dinosaurs, the coprolites, together with other ichnological evidence, such as bite marks, seem to largely illustrate the activity of the crocodylomorphs in this ancient swamp. The assemblage is compared to previously analysed continental Cretaceous copro-assemblages from Europe and North Africa.