Protoceratops Ceratopsia Leptoceratops Yinlong Zuniceratops Marginocephalia Styracosaurus Pentaceratops Beg tse Homalocephale Wannanosaurus Centrosaurinae Pachycephalosauria Ceratopsidae Stygimoloch Centrosaurus Triceratops Pachycephalosaurus Psittacosaurus