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Re: Psittacosaurus histology and postural change during growth

From: Ben Creisler

Note that the pdfs of the article and the supplement are available at:



On Fri, Jun 28, 2013 at 8:34 AM, Ben Creisler <bcreisler@gmail.com> wrote:
> From: Ben Creisler
> bcreisler@gmail.com
> A new online paper:
> Qi Zhao, Michael J. Benton, Corwin Sullivan, P. Martin Sander & Xing Xu (2013)
> Histology and postural change during the growth of the ceratopsian
> dinosaur Psittacosaurus lujiatunensis.
> Nature Communications 4(2079)
> doi:10.1038/ncomms3079
> http://www.nature.com/ncomms/2013/130628/ncomms3079/full/ncomms3079.html
> A few dinosaurs are inferred to have undergone an ontogenetic shift
> from quadrupedal-to-bipedal posture, or vice versa, based on skeletal
> allometry. The basal ceratopsian Psittacosaurus lujiatunensis is
> considered to have been mainly bipedal as an adult. Here we infer a
> postural shift in this species based on a novel combination of limb
> measurements and histological data. The forelimb is strongly
> negatively allometric relative to the hindlimb, and patterns of
> vascular canal orientation provide evidence that growth of the
> hindlimb was particularly rapid during the middle part of ontogeny.
> Histology also makes it possible to determine the ontogenetic ages of
> individual specimens, showing that the forelimb-to-hindlimb ratio
> changed rapidly during the first or second year of life and thereafter
> decreased gradually. Occurrence of an ontogenetic shift from
> quadrupedality to bipedality was evidently widespread in dinosaurs,
> and may even represent the ancestral condition for the entire group.
> A news release:
> http://phys.org/news/2013-06-exploring-dinosaur-growth.html