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Cranial Anatomy of Wendiceratops pinhornensis gen. et sp. nov., a Centrosaurine Ceratopsid (Dinosauria: Ornithischia) from the Oldman Formation (Campanian), Alberta, Canada, and the Evolution of Ceratopsid Nasal Ornamentation.

Evans DC, Ryan MJ - PLoS ONE (2015)

Bottom Line: We describe a new taxon of a highly adorned basal centrosaurine, Wendiceratops pinhornensis gen. et sp. nov., from the lower part of the Oldman Formation (middle Campanian, approximately 78-79 Ma), Alberta, Canada.Although the morphology of the nasal is incompletely known, Wendiceratops is inferred to have a large, upright nasal horn located close to the orbits, which represents the oldest occurrence of this feature in Ceratopsia.Given the phylogenetic position of the new taxon within Centrosaurinae, a enlarged nasal horn is hypothesized to have arisen independently at least twice in ceratopsid evolution.

View Article: PubMed Central - PubMed

Affiliation: Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, M5S 2C6 Canada; Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2 Canada.

ABSTRACT
The fossil record of ceratopsid dinosaurs between the occurrence of their proximate sister taxa in the Turonian and the beginning of their well-documented radiation from the late Campanian of North America onwards (approximately 90 and 77 Ma) is poor, with only seven taxa described from this early period in their evolution. We describe a new taxon of a highly adorned basal centrosaurine, Wendiceratops pinhornensis gen. et sp. nov., from the lower part of the Oldman Formation (middle Campanian, approximately 78-79 Ma), Alberta, Canada. Over 200 bones derived from virtually all parts of the skeleton, including multiple well-preserved specimens of the diagnostic parietosquamosal frill, were collected from a medium-density monodominant bonebed, making the new taxon one of the best-represented early ceratopsids. The new taxon is apomorphic in having epiparietals at loci 2 and 3 developed as broad-based, pachyostotic processes that are strongly procurved anterodorsally to overhang the posterior and lateral parietal rami, and an ischium with a broad, rectangular distal terminus. Although the morphology of the nasal is incompletely known, Wendiceratops is inferred to have a large, upright nasal horn located close to the orbits, which represents the oldest occurrence of this feature in Ceratopsia. Given the phylogenetic position of the new taxon within Centrosaurinae, a enlarged nasal horn is hypothesized to have arisen independently at least twice in ceratopsid evolution.

No MeSH data available.


Related in: MedlinePlus

Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.Illustration by Danielle Dufault.
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pone.0130007.g016: Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.Illustration by Danielle Dufault.

Mentions: The well-developed procurved ornamentation of the parietosquamosal frill sets Wendiceratops pinhornensis apart from all known centrosaurine ceratopsid taxa (Figs 15 and 16). Although Wendiceratops shares a prominent procurved ep 1 process with numerous centrosaurine taxa (e.g., Centrosaurus, Coronosaurus, Xenoceratops), it is apomorphic in expressing the remaining epiparietals as strongly procurved processes. Wendiceratops is posited as the sister taxon to Sinoceratops from China, which occurs in? Campanian strata of the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China [30, 43]. Although the medially positioned epiparietals of Sinoceratops also have a dorsal inflection, as do the apices of some of the laterally positioned epiparietals of Albertaceratops, their curvature is not nearly as well developed as in Wendiceratops. Wendiceratops can be further differentiated from Sinoceratops, as well as the basal centrosaurines Nasutuceratops and Avaceratops, by the lack of the epiparietal that occupies the posterior midline margin (ep 0). Wendiceratops also lacks the unusual series of dorsal eminences on the posterior parietal that are apomorphic of Sinoceratops [30].


Cranial Anatomy of Wendiceratops pinhornensis gen. et sp. nov., a Centrosaurine Ceratopsid (Dinosauria: Ornithischia) from the Oldman Formation (Campanian), Alberta, Canada, and the Evolution of Ceratopsid Nasal Ornamentation.

Evans DC, Ryan MJ - PLoS ONE (2015)

Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.Illustration by Danielle Dufault.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496092&req=5

pone.0130007.g016: Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.Illustration by Danielle Dufault.
Mentions: The well-developed procurved ornamentation of the parietosquamosal frill sets Wendiceratops pinhornensis apart from all known centrosaurine ceratopsid taxa (Figs 15 and 16). Although Wendiceratops shares a prominent procurved ep 1 process with numerous centrosaurine taxa (e.g., Centrosaurus, Coronosaurus, Xenoceratops), it is apomorphic in expressing the remaining epiparietals as strongly procurved processes. Wendiceratops is posited as the sister taxon to Sinoceratops from China, which occurs in? Campanian strata of the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China [30, 43]. Although the medially positioned epiparietals of Sinoceratops also have a dorsal inflection, as do the apices of some of the laterally positioned epiparietals of Albertaceratops, their curvature is not nearly as well developed as in Wendiceratops. Wendiceratops can be further differentiated from Sinoceratops, as well as the basal centrosaurines Nasutuceratops and Avaceratops, by the lack of the epiparietal that occupies the posterior midline margin (ep 0). Wendiceratops also lacks the unusual series of dorsal eminences on the posterior parietal that are apomorphic of Sinoceratops [30].

Bottom Line: We describe a new taxon of a highly adorned basal centrosaurine, Wendiceratops pinhornensis gen. et sp. nov., from the lower part of the Oldman Formation (middle Campanian, approximately 78-79 Ma), Alberta, Canada.Although the morphology of the nasal is incompletely known, Wendiceratops is inferred to have a large, upright nasal horn located close to the orbits, which represents the oldest occurrence of this feature in Ceratopsia.Given the phylogenetic position of the new taxon within Centrosaurinae, a enlarged nasal horn is hypothesized to have arisen independently at least twice in ceratopsid evolution.

View Article: PubMed Central - PubMed

Affiliation: Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, M5S 2C6 Canada; Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2 Canada.

ABSTRACT
The fossil record of ceratopsid dinosaurs between the occurrence of their proximate sister taxa in the Turonian and the beginning of their well-documented radiation from the late Campanian of North America onwards (approximately 90 and 77 Ma) is poor, with only seven taxa described from this early period in their evolution. We describe a new taxon of a highly adorned basal centrosaurine, Wendiceratops pinhornensis gen. et sp. nov., from the lower part of the Oldman Formation (middle Campanian, approximately 78-79 Ma), Alberta, Canada. Over 200 bones derived from virtually all parts of the skeleton, including multiple well-preserved specimens of the diagnostic parietosquamosal frill, were collected from a medium-density monodominant bonebed, making the new taxon one of the best-represented early ceratopsids. The new taxon is apomorphic in having epiparietals at loci 2 and 3 developed as broad-based, pachyostotic processes that are strongly procurved anterodorsally to overhang the posterior and lateral parietal rami, and an ischium with a broad, rectangular distal terminus. Although the morphology of the nasal is incompletely known, Wendiceratops is inferred to have a large, upright nasal horn located close to the orbits, which represents the oldest occurrence of this feature in Ceratopsia. Given the phylogenetic position of the new taxon within Centrosaurinae, a enlarged nasal horn is hypothesized to have arisen independently at least twice in ceratopsid evolution.

No MeSH data available.


Related in: MedlinePlus