The first hadrosauroid eggshell from the Aix-en-Provence Basin (late Maastrichtian) of France

Abstract

Nearly all dinosaur egg or oospecies occurrences from the Upper Cretaceous of France have been attributed to titanosaur dinosaurs. Here, we describe the first occurrence of probable hadrosauroid eggshells from France, which we assign to a new oospecies, Paraspheroolithus porcarboris oosp. nov. (oofamily: Spheroolithidae), from the upper ‘Argiles et Grès à Reptiles’ Formation (upper Maastrichtian) of Aix-en-Provence. Paraspheroolithus porcarboris differs from all other spheroolithid oospecies in the following combination of characteristics: prolatospherulitic morphotype, prolatocanaliculate pore system, prominent anastomosing ornamentation, medium eggshell thickness, less defined horizontal accretion lines and high pore density. The spheroolithid affinity places the new ootaxon outside oofamilies ascribed to titanosaurs (i.e. Megaloolithidae and Fusioolithidae), and thus its discovery expands the parataxonomic diversity of this region and formation. We suggest the taxonomic affinity of Spheroolithidae is somewhat broader than Hadrosauroidea, potentially encompassing all Ornithopoda. However, a hadrosauroid affinity remains the most plausible for Paraspheroolithus porcarboris based on the absence of other ornithopod remains from late Maastrichtian deposits of the Ibero-Armorican Island.