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Re: Aquilops, new ceratopsian from Lower Cretaceous of Montana, oldest in North America

And about the artistic reconstruction:


On Wed, Dec 10, 2014 at 11:26 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> Ben Creisler
> bcreisler@gmail.com
> New in PLoS ONE:
> Andrew A. Farke, W. Desmond Maxwell, Richard L. Cifelli &  Mathew J.
> Wedel (2014)
> A Ceratopsian Dinosaur from the Lower Cretaceous of Western North
> America, and the Biogeography of Neoceratopsia.
> PLoS ONE 9(12): e112055.
> doi:10.1371/journal.pone.0112055
> http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0112055
> The fossil record for neoceratopsian (horned) dinosaurs in the Lower
> Cretaceous of North America primarily comprises isolated teeth and
> postcrania of limited taxonomic resolution, hampering previous efforts
> to reconstruct the early evolution of this group in North America. An
> associated cranium and lower jaw from the Cloverly Formation
> (?middle–late Albian, between 104 and 109 million years old) of
> southern Montana is designated as the holotype for Aquilops americanus
> gen. et sp. nov. Aquilops americanus is distinguished by several
> autapomorphies, including a strongly hooked rostral bone with a
> midline boss and an elongate and sharply pointed antorbital fossa. The
> skull in the only known specimen is comparatively small, measuring 84
> mm between the tips of the rostral and jugal. The taxon is interpreted
> as a basal neoceratopsian closely related to Early Cretaceous Asian
> taxa, such as Liaoceratops and Auroraceratops. Biogeographically, A.
> americanus probably originated via a dispersal from Asia into North
> America; the exact route of this dispersal is ambiguous, although a
> Beringian rather than European route seems more likely in light of the
> absence of ceratopsians in the Early Cretaceous of Europe. Other
> amniote clades show similar biogeographic patterns, supporting an
> intercontinental migratory event between Asia and North America during
> the late Early Cretaceous. The temporal and geographic distribution of
> Upper Cretaceous neoceratopsians (leptoceratopsids and ceratopsoids)
> suggests at least intermittent connections between North America and
> Asia through the early Late Cretaceous, likely followed by an interval
> of isolation and finally reconnection during the latest Cretaceous.
> News and blogs:
> http://blogs.plos.org/paleo/2014/12/10/aquilops-hello/
> http://news.nationalgeographic.com/news/2014/12/141210-ceratopsian-aquilops-dinosaur-fossil-paleontology-science/
> http://www.snomnh.ou.edu/Aquilops_Dinosaur
> http://westerndigs.org/oldest-horned-dinosaur-in-north-america-discovered-in-montana/
> http://phys.org/news/2014-12-oldest-horned-dinosaur-species-north.html
> http://www.livescience.com/49086-oldest-horned-dinosaur-fossil.html
> http://www.livescience.com/49082-photos-oldest-horned-dinosaur.html