Late Cretaceous dinosaur eggshells from the Tremp Basin, Southern Pyrenees.

Abstract

Late Cretaceous dinosaur eggshell assemblages from six localities of the Tremp basin (Southern Pyrenecs. Lleida, Spain) are studied and compared wtth 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 Rattle-type eggshell (Ageroolithus)(mtllongensis new genus and species) and a new Prismatoolithidae are described: four other tax a are shared wit.h Southern. France. The correlation of both Spanish and French eggshell successions allows us to recognize three mam penods 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 and species). a new Rattle-type eggshell (Ageroolithus)(millongensis new genus and species) and a new Prismatoolithidae are described: four other tax a are shared with Southern France. The correlation of both Spanish and French eggshell successions allows us to recognize three mam periods characterised by different eggshell assemblages: a lower assemblage with Megaloolithus petrata: M. aureliensis, one with M. siruguei from the Middle Rognacian and Biscarri: and a late one from the Late Rognacian with M. mammilare (from Abella Bastus) and M. pseudomantlare (from Suterranya). Some contractions appear when comparing results with paleomagnetism and charophyte correlations but the eggshell correlations are consistent whit other stratgraphic studies.