Temporal range: Upper Cretaceous
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.
- Arbour, Victoria M.; Burns, Michael E.; Sissons, Robin L. (2009). "A redescription of the ankylosaurid dinosaur Dyoplosaurus acutosquameus Parks, 1924 (Ornithischia: Ankylosauria) and a revision of the genus". Journal of Vertebrate Paleontology. 29 (4): 1117–1135. doi:10.1671/039.029.0405. S2CID 85665879.