Saurolophus, meaning “lizard crest,” is a genus of hadrosaurid dinosaur from the Late Cretaceous Period (70 million years ago) of what is now North America and Asia. It is one of the few genera of dinosaurs that is known from multiple continents. The first specimen was described by paleontologist Barnum Brown in 1911. The skeleton is now on display at the American Museum of Natural History and is the first nearly complete dinosaur skeleton found in Canada. It was found in rocks of the early Maastrichtian age in the Upper Cretaceous Horseshoe Canyon Formation near Tolman Ferry on Red Deer River in Alberta.

There are two valid species of Saurolophus: the type species, S. osborni, and another species, S. angustirostris. The type species is known from at least fifteen specimens. S. osborni (Alberta) was about 32 feet long at adulthood, with a 3.3-foot-long skull, and weighed 2.1 tons. S. angustirostris (Mongolia) was larger at 39.4 feet long. The two species are virtually identical otherwise.

Saurolophus’ most distinguishing feature was its cranial crest, which would have been present in young individuals, but smaller. It was long and spike-like and projected upward and backward at about a 45 degree angle, starting from over the eyes. The crest has been described as solid, but appeared to be solid only at the point, with internal chambers that may have served as respiratory or thermo-regulatory chambers.

Saurolophus was a bipedal/quadrupedal herbivore, eating a variety of plants. Its skull permitted a grinding motion analogous to chewing, and its teeth were continually replaced throughout life. Its dental batteries contained hundreds of teeth. It would have cropped plant material with its broad beak, and held food in its jaw by a cheek-like organ. It would have fed on vegetation from ground level up to about 13 feet.