Platytholus

Platytholus is an extinct genus of pachycephalosaurid from the Late Cretaceous (Maastrichtian) Hell Creek Formation of the United States. The genus contains a single species, P. clemensi, known from a partial skull. It was a medium-sized pachycephalosaur, living alongside its smaller relative Sphaerotholus and larger relative Pachycephalosaurus. Compared to other pachycephalosaurs, its dome had a distinct low and broad rectangular shape and unique roof-tile like ornamentation along its sides. Though it has been found as a potential relative of Prenocephale, its phylogenetic position remains uncertain due to the fragmentary nature of the only known specimen.