Reptilia - Ornithischia - Pachycephalosauridae
Full reference: P. C. Sereno. 1997. The origin and evolution of dinosaurs. Annual Review of Earth and Planetary Sciences 25:435-489
Parent taxon: Pachycephalosauridae according to P. C. Sereno 2000
See also Gangloff et al. 2005, Sereno 1997, Sereno 1998, Sereno 1999, Sullivan 2003, Williamson and Carr 2003, Williamson and Carr 2006, Williamson et al. 2009, Woodruff et al. 2021 and Woodruff et al. 2025
Sister taxa: Amtocephale, Colepiocephale, Hanssuesia, Pachycephalosaurini, Sinocephale, Texacephale, Tylocephale, Domocephalinae
Subtaxa: Acrotholus Brontotholus Foraminacephale Platytholus Sphaerotholus
Ecology: ground dwelling herbivore
Distribution:
• Cretaceous of Canada (11: Alberta, Saskatchewan collections), United States (7: Montana, New Mexico)
Total: 18 collections each including a single occurrence