[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: [dinosaur] Evolution of ornithischian quadrupedality



Hmmm.... Now the link is back to paywall and only the abstract is posted, not the full text. Sorry for the confusion.

Virus-free. www.avg.com

On Thu, Oct 19, 2017 at 7:52 AM, Ben Creisler <bcreisler@gmail.com> wrote:

Not quite sure what's going on. The full text of the paper is now posted  online at the link, but the the free pdf download does not seem to work for me. Does the pdf link download for anybody?

https://link.springer.com/article/10.1007/s41513-017-0036-0?no-access=true

On Thu, Oct 12, 2017 at 8:27 AM, Ben Creisler <bcreisler@gmail.com> wrote:

Ben Creisler


A new paper:


Paul M. Barrett & Susannah C. R. Maidment  (2017)
The evolution of ornithischian quadrupedality.
Journal of Iberian Geology (advance online publication)




Ornithischian dinosaurs were primitively bipedal, but reverted to quadrupedality on at least three (and potentially several more) occasions: in Ceratopsia, Thyreophora and Hadrosauriformes. Each of these reversals was accompanied by anatomical changes to the whole skeleton that enabled the forelimb to function in weight bearing and that also resulted in numerous changes to the hip and hind limb musculature. Each quadrupedal clade acquired a suite of similar biomechanical characters, although they varied in terms of function and in how these character complexes were assembled. Some similar changes occurred in parallel among sauropodomorph dinosaurs as they transitioned from bipedality to quadrupedality. It is unclear why bipedal ornithischians reverted to quadrupedalism, but neither increases in body size nor the acquisition of dermal armour seem to have played a significant role. Increased head size might have influenced the position of the centre of mass and stance in ceratopsians and it is plausible that the evolution of herbivory played an important role in both ornithischians and sauropods, but the latter hypothesis is difficult to test.


Virus-free. www.avg.com