Saurolophus

Saurolophus (; meaning "lizard crest") is a genus of large hadrosaurid dinosaur that lived during the Late Cretaceous period of North America and Asia, in what is now the Horseshoe Canyon and Nemegt formations respectively (about 70 to 66 million years ago). It is one of the few dinosaur genera known from multiple continents. The type species, S. osborni, was described by Barnum Brown in 1912 from Canadian fossils. A second valid species, S. angustirostris, is represented by numerous specimens from Mongolia, and was described by Anatoly Konstantinovich Rozhdestvensky. Saurolophus is distinguished by a spike-like crest which projects up and back from the skull. It was a herbivorous dinosaur which could move either bipedally or quadrupedally.

==Discovery and history== thumb|left|Photo from the excavation of S. osborni in 1911 Barnum Brown recovered the first described remains of Saurolophus in 1911, including a nearly complete skeleton (AMNH 5220). Now on display in the American Museum of Natural History, this skeleton was the first nearly complete dinosaur skeleton from Canada. It was found in rocks of early Maastrichtian age, in the Upper Cretaceous Horseshoe Canyon Formation (then known as the Edmonton Formation) near Tolman Ferry on the Red Deer River in Alberta. Brown wasted little time in describing his material, giving it its own subfamily. Saurolophus was an important early reference for other hadrosaurs, as seen in the names of Prosaurolophus ("before Saurolophus") and Parasaurolophus ("near Saurolophus"). However, little additional material has been recovered and described.