[Paleontology • 2015]
Wendiceratops pinhornensis • A Centrosaurine Ceratopsid (Dinosauria: Ornithischia) from the Oldman Formation (Campanian), Alberta, Canada, and the Evolution of Ceratopsid Nasal Ornamentation
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Wendiceratops pinhornensis
Evans & Ryan, 2015
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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.
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Fig 3. Skeletal reconstruction of Wendiceratops pinhornensis gen. et sp. nov.
Elements represented in the material collected from the bonebed are indicated in blue.
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Systematic Palaeontology
Dinosauria Owen, 1842
Ornithischia Seeley, 1887
Ceratopsia Marsh, 1890
Neoceratopsia Sereno, 1986
Ceratopsidae Marsh, 1888
Centrosaurinae Lambe, 1915
Wendiceratops gen. nov.
urn:lsid:zoobank.org:act:BEE8D424-8BB0-4335-BFFC-701E2C8B4DB3
Diagnosis: Monotypic, as for species.
Wendiceratops pinhornensis, gen. et. sp. nov.
urn:lsid:zoobank.org:act:22F3BE83-6045-489D-8F2D-FE53FC08A175
Etymology: The generic name honors Wendy Sloboda, who discovered the type locality, combined with ceratops (horned-face) from the Greek, a common suffix for horned dinosaur generic names. The specific epithet refers to the Pinhorn Provincial Grazing Reserve in Alberta, Canada, where the type locality is located.
Holotype: TMP 2011.051.0009, an incomplete parietal lacking the midline bar and left ramus.
Locality, horizon and age: The type locality occurs within the
boundaries of the Pinhorn Provincial Grazing Reserve, south of the Milk
River, County of Forty Mile No.8, Alberta, Canada.
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Fig 2. Quarry map for the South Side Ceratopsian bonebed.
This bonebed has produced all of the known Wendiceratops pinhornensis gen. et sp.
nov. material to date. Elements outlined in gray were collected in 2011
and their positions are approximate relative to the more precisely
mapped bones collected in 2013 and 2014 (outlined in black). Inset rose
diagram denotes a slight NE-SW trend in long axis orientation for the
elements over 100 mm in length. See text for comments on the taphonomy
of the bonebed.
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Fig 16. Life reconstruction of Wendiceratops pinhornensis gen. et sp. nov.
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David C. Evans and Michael J. Ryan. 2015. 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.
PLOS ONE. 10(7): e0130007. doi:
10.1371/journal.pone.0130007
Horned dinosaur discovery sheds light on nose horn evolution in Tricerat...
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