Neornithischia

Neornithischians Temporal range: Early Jurassic–Late Cretaceous, 199.6–65.5Ma PreЄ Є O S D C P T J K Pg N
Skulls of neornithischian dinosaurs
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Order:	†Ornithischia
Clade:	†Genasauria
Clade:	†Neornithischia Cooper, 1985
Subgroups
†Agilisaurus †Alocodon †Ferganocephale †Gongbusaurus †Hexinlusaurus †Nanosaurus †Othnielia †Othnielosaurus †Phyllodon †Stormbergia †Xiaosaurus †Cerapoda

Life restoration of Stormbergia (above) and Othnielosaurus (bottom)

Neornithischia ("new ornithischians") is a clade of the dinosaur order Ornithischia. They are the sister group of the Thyreophora within the clade Genasauria. Neornithischians are united by having a thicker layer of asymmetrical enamel on the inside of their lower teeth. The teeth wore unevenly with chewing and developed sharp ridges that allowed neornithischians to break down tougher plant food than other dinosaurs.

Preliminary reports based on an as-yet unnamed species of Jurassic neornithischian show that, like theropods, and heterodontosaurids, at least some neornithischians were covered in both scales and feathers.^[1] Feather-like structures have also been reported in the neornithischian Psittacosaurus.

Classification

Neornithischia was first named by Cooper in 1985 and defined as "all genasaurians more closely related to Parasaurolophus walkeri Parks, 1922, than to Ankylosaurus magniventris Brown, 1908 or Stegosaurus stenops Marsh, 1877a".^[2] The cladogram below follows a 2011 analysis by paleontologists Richard J. Butler, Jin Liyong, Chen Jun and Pascal Godefroit.^[3]

References

• Butler, R.J. (2005). Zoological Journal of the Linnean Society 145 (2). p. 175-18. 
• Sereno, P.C. (1986). "Phylogeny of the bird-hipped dinosaurs (order Ornithischia)". National Geographic Research 2 (2): 234–56. 

External links

• Encyclopædia Britannica
• Palæos