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Dinosaur Posture Still Wrong, Says Study
An anonymous reader sends along a piece in Cosmos about new dissension to the current prevailing wisdom on dinosaur posture. The researchers admit that blood pressure presents an unresolved obstacle to their model of dinosaur heads held high. "The current depiction of the way giant sauropod dinosaurs held their necks is probably wrong, says a new study. 'For the last decade the reigning paradigm in palaeontology has been that the big sauropod dinosaurs held their necks out straight and their heads down low,' said co-author Matt Wedel, who researches biomechanics at the Western University of Health Sciences in Pomona, California. But 'our research [now] suggests that this view of sauropods is simply incorrect, based on everything we know about living animals,' he said." The researchers worried that some other team might beat them to publication, so obvious did they consider their methodology of looking at living animals to gain insight into the biomechanics of extinct ones.
So they looked at a giraffe and decided that the giraffe may be a suitable long-necked living animal? Unfortunately TFS only says that the horizontal configuration is incorrect, and I can't get to the article to see how they posit that long-necked animals posture themselves. So, I'm suggesting that the long neck is held vertically as a way of gaining extra height for food reach, reaching the ground, and longer range vision without the increased bulk of longer legs, taller body, etc.
Is it sad that I am more likely to recognize you and your posts by your sig than your name or UID?
This is all informed speculation - interesting, and it generates a testable hypothesis, but hardly revealing. There's a hundred different ways to go on the issue until they find impressions of soft tissue. The authors (of the paper, not TFA) hedge their bets heavily by saying that IF sauropods are directly comparable to extant taxa... a bet I wouldn't take myself, since sauropods seemed to form a morphoniche we don't see _appreciably_ filled in extant groups (obvious exception excluded).
For people who want their science undiluted, here's the paper: http://www.app.pan.pl/article/item/app54-213.html
Head and neck posture in sauropod dinosaurs inferred from extant animals
Michael P. Taylor, Mathew J. Wedel, and Darren Naish
Acta Palaeontologica Polonica 54 (2), 2009: 213-220
Re: modern pseudo-analogues -- based upon the geese I raised as a kid, I never could quite grok the 'head-held-low' posture. Geese only hold their heads low to screw or to attack.
I think it's dangerous to try to compare a two legged winged creature to a four legged creature but from the article:
They found that reptiles and amphibians held their necks mostly horizontally, while mammals and birds (which are more closely related to dinosaurs and share their upright leg structures) all held their necks vertically.
Studying the neck movements of living creatures also suggested that sauropods had a greater range of movement than previously thought.
While scientists had assumed that the dinosaur neck vertebrae overlapped each other by around 50%, that's not true for living creatures like ostriches and giraffes, which can extend their necks till the vertebrae hardly overlap at all.
And in regards to efficiency of the way they hold their neck:
It seems very inefficient for a large creature to hold that much weight horizontally away from the body (remember those physics lessons re: levers and distance from the fulcrum?).
(As the article notes) it's probably a lot harder to have the blood pressure to pump blood all the way up that column to the head. Blood pressure is one of the things they can't explain about their model. The article says, "Estimates of blood pressure also suggested that it would have been very difficult for sauropods to pump their blood up to such a height."
Dinosaurs are awesome, as most five-year-olds will tell you. Armchair paleontology is fun too. And since we slashdotters are so fond of pretending expertise on subjects we know little about, and TFA seems to be slashdotted, I'm looking forward to a very amusing (but maybe not quite so enlightening) discussion.
After reading it, the article's not as great as you think. There's plenty of pictures on Wikipedia of the animals depicted both ways.
My work here is dung.