Brachylophosaurus

Brachylophosaurus ( or ) is a genus of hadrosaurid dinosaur that lived during the Late Cretaceous period of western North America. It was first named in 1953 by Charles Mortram Sternberg for a skull and skeleton he discovered in 1936 in the Oldman Formation of Alberta, Canada, for which he named the new taxon Brachylophosaurus canadensis. While this single specimen was the only known material of Brachylophosaurus for a long time, extensive discoveries in the Judith River Formation of Montana, USA have uncovered not only additional skulls and skeletons with extensive impressions of skin, but also a bonebed of 800 specimens. The earliest of these discoveries in Montana was named Brachylophosaurus goodwini by John R. Horner, but it is now believed that there was only a single species of Brachylophosaurus, with B. goodwini as either a junior synonym of B. canadensis or an indeterminate member of Brachylophosaurini.

==Discovery and species== thumb|left|Type skull of Brachylophosaurus CMN 8893 In 1936, American paleontologist Charles Mortram Sternberg led an expedition of the Geological Survey of Canada to the region of Dinosaur Provincial Park, Alberta, collecting multiple specimens for the Canadian Museum of Nature including a skull and partial skeleton of a hadrosaur (CMN 8893). This specimen was found in a thin sandstone bed of the Oldman Formation above the mouth of Little Sandhill Creek on the Red Deer River, above the water level. Sternberg labelled this quarry, near Steveville, Alberta, as quarry No. 58, and though he marked it with a stake and identified it on a map, it was lost for more than 20 years as the back wall had collapsed and buried the marker, only being rediscovered in 2001 and officially designated Q103. When first collected, Sternberg believed that CMN 8893 represented a new species of the hadrosaur Gryposaurus, but additional study led to his reinterpretation of the specimen as quite distinct and in need of a new genus, superficially similar to Gryposaurus and Kritosaurus but likely closer to Saurolophus. As such, in 1953 Sternberg named CMN 8893 Brachylophosaurus canadensis, identifying it as a relative of all aforementioned hadrosaurs within the subfamily Hadrosaurinae. The genus name comes from the Ancient Greek words βραχύς (brakhús), meaning "short", λόφος (lóphos), meaning "crest", and σαῦρος (saûros), meaning "lizard".