Saurolophus is a genus of large hadrosaurine duckbill that lived about 70 million years ago, in the Late Cretaceous of North America (Canada) and Asia (Mongolia); it is one of the few genera of dinosaurs known from multiple continents. It is distinguished by a spike-like crest which projects up and back from the skull. Saurolophus was a herbivorous dinosaur which could move about either bipedally or quadrupedally.
The type species, S. osborni, was described by Barnum Brown in 1912. The other valid species, S. angustirostris, lived in Asia, and was described by Anatoly Konstantinovich Rozhdestvensky. A third species is considered dubious.