Saurolophus

Saurolophus was a duck-billed dinosaur. It lived during the Upper Cretaceous period, 69.5-68.5 million years ago, toward the end of the Mesozoic Era.
"Saurolophus" had a 5 inch (13 cm) long bony spike extending up from its forehead. There is speculation that this spike was attached to a flap of skin that covered the nostrils and could be blown up for displays and noise-making. Many "Saurolophus" fossils have been found, including one with fossilized skin impressions, in Alberta, Canada and Mongolia, China.