In 1943, Barnum Brown and Erich Maren Schlaikjer, with newer, more complete material, established the genus "Pachycephalosaurus". They named two species: "Pachycephalosaurus grangeri", the type species of the genus "Pachycephalosaurus", and "Pachycephalosaurus reinheimeri". "P. grangeri" was based on AMNH 1696, a nearly complete skull from the Hell Creek Formation of Ekalaka, Carter County, Montana. "P. reinheimeri" was based on what is now DMNS 469, a dome and a few associated elements from the Lance Formation of Corson County, South Dakota. They also referred the older species "Troodon" "wyomingensis" to their new genus. Their two newer species have been considered synonymous with "P. wyomingensis" since 1983.