Late Cretaceous dinosaur eggshells from the Tremp Basin, southern Pyrenees, Lleida, Spain

Late Cretaceous dinosaur eggshell assemblages from six localities of the Tremp basin (Southern Pyrenees, Lleida, Spain) are studied and compared with those of Southern France, to correlate their temporal succession. Fontllonga 6 reveals the most diverse eggshell assemblage known so far, with seven oospecies, among which one new structural type ( Pseudogeckoolithus nodosus new genus and species), a new Ratite-type eggshell ( Ageroolithus fontllongensis new genus and species) and a new Prismatoolithidae are described; four other taxa are shared with Southern France. The correlation of both Spanish and French eggshell successions allows us to recognize three main periods characterised by different eggshell assemblages: a lower assemblage with Megaloolithus petralta, M. aureliensis, Prismatoolithus tenuis and P. matellensis from the French Lower Rognacian and the Spanish sites Fontllonga 6 and Moro; a middle one with M. siruguei from the Middle Rognacian and Biscarri; and a late one from the Late Rognacian with M. mammilare (from Abella and Bastus) and M. pseudomamillare (from Suterranya). Some contradictions appear when comparing results with paleomagnetism and charophyte correlations but the eggshell correlations are consistent with other stratigraphic studies.