Researchers in northeastern Spain say they've uncovered hundreds of dinosaur egg fossils, including four kinds that had never been found before in the region. The eggs likely were left behind by sauropods millions of years ago. Eggs, eggshell fragments and dozens of clutches were nestled in the stratigraphic layers of the Tremp geological formation at the site of Coll de Nargó in the Spanish province of Lleida, which was a marshy region during the Late Cretaceous Period, the researchers said.