Colepiocephale

Colepiocephale (meaning "knucklehead") is a genus of pachycephalosaurid dinosaur from Late Cretaceous (middle Campanian stage) deposits of Alberta, Canada. It was collected from the Foremost Formation. The type species, C. lambei, was originally described by Sternberg in 1945 as Stegoceras lambei, and later renamed by Sullivan in 2003. C. lambei is a domed pachycephalosaur characterized principally by the lack of a lateral and posteriosquamosal shelf, a steeply down-turned parietal, and the presence of two incipient nodes tucked under the posterior margin of the parietosquamosal border.

==History of naming== thumb|left|Life reconstruction In 1923, a partial skull was collected from the Oldman Formation of Alberta by E.J. Whitaker, as the only fossil found at a locality below Bow Island ferry along the South Saskatchewan River and below the top of the Oldman Formation. It was acquired by the Geological Survey of Canada where it gained the accession number GSC No. 8818. GSC 8818 was first described by American palaeontologists Barnum Brown and Erich Maren Schlaikjer in 1943 as a specimen of the pachycephalosaur Troodon validus, which had earlier been given the name Stegoceras validus but was not believed to be a distinct genus by Brown and Schlaijker. This identification was disputed by American palaeontologist Charles Mortram Sternberg in 1945, who showed that Troodon, for a time believed to be a pachycephalosaur, was instead a carnivorous theropod, who as a result revived Stegoceras as well as named the new family Pachycephalosauridae to house pachycephalosaurs. Sternberg also recognized that GSC 8818 was a separate species from S. validus, and created the new species Stegoceras lambei with GSC 8818 as the holotype. The species name was in honour of the deceased Canadian palaeontologist Lawrence M. Lambe.