Neornithischia
| Neornithischians Temporal range: Early Jurassic–Late Cretaceous, 199.6–66 Ma | |
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| Skulls of neornithischian dinosaurs | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Order: | †Ornithischia |
| Clade: | †Genasauria |
| Clade: | †Neornithischia Cooper, 1985 |
| Subgroups | |
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.
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".[1] The cladogram below follows a 2011 analysis by paleontologists Richard J. Butler, Jin Liyong, Chen Jun and Pascal Godefroit.[2]
| Neornithischia |
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A recent study by Matthew G. Baron, David B. Norman and Paul M. Barrett recovered the Early Jurassic taxon Lesothosaurus diagnosticus from Southern Africa as the most basal known member of Neornithischia – a position previously held by Stormbergia dangershoeki (a taxon considered by the authors to be an adult form of Lesothosaurus and therefore a junior subjective synonym). However, Baron et al. go on to state that this result is only poorly supported and that future studies will be needed in order to better resolve the base of the ornithischian tree. The cladogram below follows Baron et al. 2016.[3]
| Neornithischia |
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References
- ↑ Richard J. Butler; Paul Upchurch; David B. Norman (2008). "The phylogeny of the ornithischian dinosaurs". Journal of Systematic Palaeontology. 6 (1): 1–40. doi:10.1017/S1477201907002271.
- ↑ Richard J. Butler; Jin Liyong; Chen Jun; Pascal Godefroit (2011). "The postcranial osteology and phylogenetic position of the small ornithischian dinosaur Changchunsaurus parvus from the Quantou Formation (Cretaceous: Aptian–Cenomanian) of Jilin Province, north-eastern China". Palaeontology. 54 (3): 667–683. doi:10.1111/j.1475-4983.2011.01046.x.
- ↑ Matthew G. Baron; David B. Norman; Paul M. Barrett (2016). "Postcranial anatomy of Lesothosaurus diagnosticus (Dinosauria: Ornithischia) from the Lower Jurassic of southern Africa: implications for basal ornithischian taxonomy and systematics". Zoological Journal of the Linnean Society. doi:10.1111/zoj.12434.
- Butler, R.J. (2005). "The 'fabrosaurid' ornithischian dinosaurs of the Upper Elliot Formation (Lower Jurassic) of South Africa and Lesotho". Zoological Journal of the Linnean Society. 145 (2): 175-18.
- Sereno, P.C. (1986). "Phylogeny of the bird-hipped dinosaurs (order Ornithischia)". National Geographic Research. 2 (2): 234–56.