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RE: Raised sauropod necks

Not to disagree with accredited PhDs here, but while this paper makes an 
argument that seems new, due to the press it has received, the neck-posture 
element of the paper is old data, even though the taxon selected (*Euhelopus 
zdanskyi*) is new. In a sense, it's taxon sampling is being careful, and is 
providing different data from one analysis to the other, and they are doing so 
in the best way possible: Biomechanically.

The original paper is:

Christian, A. & Dzemski, G. 2007. Reconstruction of the cervical skeleton 
posture of *Brachiosaurus brancai* Janensch, 1914 by an analysis of the 
intervertebral stress along the neck and a comparison with the results of 
different approaches. _Fossil Record_ 10:37–48. 

The two papers analyzed the cervical series of the two sauropods in the same 
way, and some to different general postures of highest stress in the 
intervertebral sections. They also do not outright dismiss Kent Stevens' work, 
which argued for a "neutral" posture with intervertebral neutrality. The best 
part of this work? Its finding different postures for different taxa. Taylor et 
al. are supported by work on both, but their posture is not the same as either 
Christian and Dzemski (2007) or Christian (2010), which sampled individual taxa 
by direct biomechanical means.

Expect more from the group.


Jaime A. Headden
The Bite Stuff (site v2)

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 

> Date: Thu, 3 Jun 2010 09:27:17 -0600
> From: rtravsky@uwyo.edu
> To: dinosaur@usc.edu
> Subject: Raised sauropod necks Re: A sauropod paper and a buttload of 
> ornithopod ones
> On Wed, 2 Jun 2010, Thomas R. Holtz, Jr. wrote:
>> Christian, A. 2010. Some sauropods raised their necks—evidence for high
>> browsing in Euhelopus zdanskyi. Biol. Lett. published online before print
>> June 2, 2010, doi:10.1098/rsbl.2010.0359
>> Abstract
>> A very long neck that is apparently suitable for feeding at great heights is
>> a characteristic feature of most sauropod dinosaurs. Yet, it remains
>> controversial whether any sauropods actually raised their necks high.
>> Recently, strong physiological arguments have been put forward against the
>> idea of high-browsing sauropods, because of the very high blood pressure
>> that appears to be inevitable when the head is located several metres above
>> the heart. For the sauropod Euhelopus zdanskyi, however, biomechanical
>> evidence clearly indicates high browsing. Energy expenditure owing to high
>> browsing is compared with energy costs for walking a distance. It is
>> demonstrated for Euhelopus as well as for the much larger Brachiosaurus that
>> despite an increase in the metabolic rate, high browsing was worthwhile for
>> a sauropod if resources were far apart.
> No disrespect, but isn't getting to be old news?
> From May 2009
> http://www.sciencedaily.com/releases/2009/05/090526213918.htm
> ...
> But now scientists are saying the low-necked sauropod pose is a mistake:
> new evidence indicates that they held their necks aloft like giraffes and
> all other living land vertebrates, making them up to 15 metres tall.
> Dr Mike Taylor and Dr Darren Naish, of the University of Portsmouth, and
> Dr Matt Wedel, of Western University of Health Sciences in California,
> argue that while sauropods could hold their necks low, it was not their
> habitual posture.
> ...
>> Open Access: just go to
>> http://rsbl.royalsocietypublishing.org/content/early/2010/05/29/rsbl.2010.03
>> 59.full
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