Marginocephalia

Marginocephalians Temporal range: Late Jurassic–Late Cretaceous, 156–66 Ma PreЄ Є O S D C P T J K Pg N
File:Triceratops 2.jpg
Skull of Triceratops horridus
Skull of Stygimoloch spinifer
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia
Clade:	†Cerapoda
Clade:	†Marginocephalia Sereno, 1986
Subgroups
See text.

Marginocephalia ("fringed heads") is a clade of ornithischian dinosaurs that includes the thick-skulled pachycephalosaurids, and horned ceratopsians. They were all herbivores, walking on two or four legs, and are characterized by a bony ridge or frill at the back of the skull. The clade evolved in the Jurassic period, and became common in the Upper Cretaceous.

Classification

The cladogram below follows a 2009 analysis by Zheng and colleagues.

Marginocephalia	Pachycephalosauria Stenopelix Wannanosaurus Goyocephale Homalocephale Pachycephalosauridae Ceratopsia Micropachycephalosaurus Chaoyangsaurus Psittacosauridae Neoceratopsia Liaoceratops Archaeoceratops Leptoceratopsidae Coronosauria

Cladogram after Butler et al., 2011.

Marginocephalia	Pachycephalosauria Wannanosaurus Goyocephale Homalocephale Pachycephalosauridae Ceratopsia Micropachycephalosaurus Chaoyangsaurus Stenopelix Yinlong Psittacosauridae Neoceratopsia Liaoceratops Archaeoceratops Leptoceratopsidae Coronosauria