Results 161 to 170 of about 989 (201)

Dental assessment of Stegoceras validum (Ornithischia: Pachycephalosauridae) and Thescelosaurus neglectus (Ornithischia: Thescelosauridae): paleoecological inferences

Cretaceous Research, 2022
Abstract Small herbivorous dinosaurs of the clades Pachycephalosauridae and Thescelosauridae occur in multiple Cretaceous formations in North America, their coexistence likely made possible by differences in feeding style. Fossils of these taxa are generally rare, but isolated pachycephalosaurid and thescelosaurid teeth are common at microfossil ...
Michael Naylor Hudgins, , Corwin Sullivan   +2 more
exaly   +3 more sources

A primitive ornithischian dinosaur from the Late Triassic of South Africa, and the early evolution and diversification of Ornithischia [PDF]

Proceedings of the Royal Society B: Biological Sciences, 2007
Although the group played an important role in the evolution of Late Mesozoic terrestrial ecosystems, the early evolutionary history of the ornithischian dinosaurs remains poorly understood.
Richard J Butler, Roger M H Smith, David B Norman   +2 more
exaly   +2 more sources

14. Basal Ornithischia

2019
David B. Norman, Lawrence M. Witmer, David B. Weishampel   +2 more
exaly   +2 more sources

Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia)

Journal of Systematic Palaeontology, 2008
Synopsis Stegosauria is a clade of ornithischian dinosaurs characterised by a bizarre array of dermal armour extending, in two parasagittal rows, from the cervical region to the end of the tail. Although Stegosaurus is one of the most familiar of all dinosaurs, little is known regarding the evolutionary history of this clade.
Maidment, Susannah, Norman, David, Barrett, Paul, Upchurch, Paul   +3 more
openaire   +1 more source

Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora)

Journal of Systematic Palaeontology, 2011
Ankylosauria is a diverse clade of quadrupedal ornithischian dinosaurs whose remains are known from Middle Jurassic to latest Cretaceous sediments worldwide. Despite a long history of research, ankylosaur interrelationships remain poorly resolved and existing cladistic analyses suffer from limited character and taxon sampling. Here, we present the most
Thompson, Richard, Parish, Jolyon, Maidment, Susannah, Barrett, Paul   +3 more
openaire   +1 more source

Notes on pachycephalosaurs (Ornithischia)

Journal of Paleontology, 1989
Previously undescribed specimens ofPachycephalosaurus wyomingensisallow partial description of the anterior braincase and a preliminary examination of change of dome shape with age. The two morphs of dome shape recognized in adults are also present in juvenile specimens with dome lengths half that of mature adults.
openaire   +1 more source

Pachycephalosaurs and Ceratopsians (Ornithischia: Marginocephalia)

Short Courses in Paleontology, 1989
Explanatory scenarios for the evolution of dinosaur anatomy are often couched in terms of competitive advantage, with those animals of superior design overtaking those that are slower and less efficient. Many, if not the majority, of the most striking structural modifications, however, are the product of competition and display between conspecifics ...
openaire   +1 more source

Pachycephalosaur paleoneurology (Archosauria: Ornithischia)

Journal of Vertebrate Paleontology, 1989
ABSTRACT Pachycephalosaur endocranial casts display a distinctive suite of traits that include large divergent olfactory bulbs, large olfactory nerves, short thick olfactory tracts, a moderately expanded cerebrum not separated from optic lobes and cerebellum dorsally, steep cranial flexure, and reduced pontine flexure.
openaire   +1 more source

Evolution of Bird-Hipped Dinosaurs (Ornithischia)

Short Courses in Paleontology, 1989
By the end of the last century, the assortment of dinosaur skeletons that had already accumulated were classified into two groups of approximately equal size based on the divergent plan of their hip bones: Saurischia, the “lizard-hipped” dinosaurs, and Ornithischia, the “bird-hipped” dinosaurs (Seeley, 1888).
openaire   +1 more source

Osteology of the Patagonian ornithopodTalenkauen santacrucensis(Dinosauria, Ornithischia)

Journal of Systematic Palaeontology, 2019
Talenkauen santacrucensis represents one of the most complete South American ornithopods yet discovered.
Rozadilla, Sebastian, Agnolín, Federico Lisandro, Novas, Fernando Emilio   +2 more
openaire   +2 more sources