Dinosaur eggshells as biochronological markers in Upper Cretaceous continental deposits

European dinosaur eggshells are now well organized in a parataxonomic classification and can be used as reliable biochronological markers for Upper Cretaceous continental deposits. The Rognacian (Campanian–Maastrichtian) continental deposits of southern France can be divided into three successive associations of megaloolithidae taxa. A maximum in ootaxa diversity occurs in Upper Campanian deposits, followed by a decrease at the Campanian–Maastrichtian transition; this correlates with a climatic change recorded in the palynological floras. The stratigraphic distribution of the oospecies demonstrates that the ‘Rognac Limestone’ found in the west and east areas of the Arc basin is diachronic.