Duckbill Skin Cast. Late Cretaceous. Duckbill is often a reference to the Hadrosaurids- including Hadrosaur, Edmontosaur, Parasaurolophus, and other such dinosaurs. They were the first dinosaur family to be identified in North America. Hadrosaurs primarily became a distinct species during the Cretaceous. Duckbill Skin Cast measures 14 cm x 10 cm.