Marginocephalia

Marginocephalia
	Chasmosaurus skeleton
Temporal occurrence
	Upper Jurassic to Upper Cretaceous ( Oxfordian to Maastrichtian )
	163.5 to 66 million years
Locations
	Worldwide;
Systematics
	Diapsida
	Archosauria
	Dinosaur (dinosauria)
	Pelvic dinosaur (Ornithischia)
	Cerapoda
	Marginocephalia
Scientific name
	Marginocephalia
	Sereno , 1986

The Marginocephalia are a taxon (a systematic group) of the bird's pelvis dinosaur (Ornithischia). In this group the Pachycephalosauria and the Ceratopsia are combined.

features

This group is characterized by a rearward protruding rear edge of the skull, which is formed from the parietal bone (parietal) and the scaly bone (squamosum). In the Ceratopsia, this structure has developed into an enlarged neck shield. The Pachycephalosauria, on the other hand, are characterized by bony cusps or spines on the scale bone , here the parietal bone together with the frontal bone forms the typical thickened skull roof. Further characteristics of Marginocephalia are the shortened pelvis and the reduction of the part of the intermaxillary bone (premaxillary) on the palate.

The Pachycephalosauria and the primeval Ceratopsia moved biped (with the hind legs), while the more developed Ceratopsia ( Ceratopsidae ) were strictly quadruped . All Marginocephalia were primarily herbivores, but it is conceivable that the Pachycephalosauria could also have consumed other foods such as small animals or eggs.

The earliest representatives of the Marginocephalia come from the early Upper Jurassic , but this taxon reached its peak during the late Cretaceous period .

Systematics

The taxon of Marginocephalia was established in 1986 by Paul Sereno . They are defined as the last common ancestor of Pachycephalosaurus and Triceratops and all of their descendants.

Within the bird pelvis dinosaurs they are counted to the group of Cerapoda , their sister group are the Ornithopoda . This is expressed in the following simplified cladogram:

dinosaur

Pelvic dinosaur (Ornithischia)

Thyreophora
(including stego- and ankylosauria )

Cerapoda

	Ornithopoda

	Marginocephalia

Lizard dinosaur (Saurischia)

literature

David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 .

Individual evidence

^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , pp. 240-272, online .
↑ Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date encyclopedia for dinosaur lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , p. 272.

[1] Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , pp. 240-272, online .

[Holtz_2007-2] Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date encyclopedia for dinosaur lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , p. 272.