A new pachycephalosaurid skull (Ornithischia) from the Cretaceous Hell Creek Formation of Montana

Abstract

ABSTRACT The new genus and species Stenotholus kohleri from the Late Cretaceous Hell Creek Formation of McCone County, Montana is a pachycephalosaurid omithischian. The species possesses a vertically high and transversely narrow dome, elimination of the parietosquamosal shelf, closure of the supratemporal fenestra in the subadult, a highly sculptured frontal, and a sagittally shortened occipital region. The possibility that this skull represents a previously described pachycephalosaurid is rejected on the basis of the unique suite of traits presented.