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.

Comments

AW...

[The Living Fractal]

Guess this means there was no Stuckupasaurus? You know, the snooty dinosaur who thought it was better than all the others and walked around holding its head high and looking down its nose at the others? ...ok, wow, THAT was lame.

I apologize.

TFA Is slashdotted

[TinBromide]

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.

Re:TFA Is slashdotted

[Red Flayer]

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.

Not only that, but I'd conjecture that the long neck must have evolved vertically. The musculature required to hold a long neck like that horizontal must be enormous, and hardly an efficient way of bearing weight. Plus, is it any coincidence that the large dinosaur neckbones look kind of like hip bones, the primary vertical weight-bearing bone in people?

And the BS about the massive tail counterbalancing a long neck... for that to work as an opposing force on the neck, with the body as a fulcrum... well... that would required the spine to be pretty rigid. I'm not sure how well that would work in practice.

On a side note, have you ever seen a giraffe try to reach the ground with their head? It's pretty amusing. It reminds me of myself, trying to pick up my kids crayons from the floor... it's a whole lot of effort (what? so I'm not in shape or flexible. That's normal here, right?)

Re:TFA Is slashdotted

[Captain Hook]

But having a 15 ft long neck which is held horizontal means you can browse a 30ft wide path without moving (or perhaps while moving slowly in one direction), the energy saving for being able to browse a large swath of ground without moving must be large when you weight a few tonnes.

Re:TFA Is slashdotted

[Minwee]

I'm pretty sure gravity is the problem

Well that's simple, just change the gravitational constant of the universe.

Re:TFA Is slashdotted

[shess]

I can't did up the reference right now, but it turns out the eneregy requirements for maintaining the long neck outweigh the cost of simply walking to the food.

Meaning dinosaurs did not have long necks. QED.

Two Things

[eldavojohn]

Why are we arguing over which position was the default when it's entirely possible that they utilized both positions. Down low for traveling to avoid blood pressure problems and up high for brief states of alert or reaching high food sources? With the flexibility of the vertebrae, I would assume the animal would use it however it most suited them for the time being.

The other thing is how much do we know about the tissues and proteins that made up muscles and blood in Sauropods? Is it possible that they were much stronger or their blood had different properties making it capable of overcoming the blood pressure problem?

I've seen exhibits that portray them both ways. You just might have to accept that you're never going to know for sure ...

... until you CLONE THEM!

*starts humming the Jurrasic Park theme song with a creepy grin on his face*

Re:Two Things

[lgw]

Giraffe's have a rete mirabile to avoid the head exploding when lowered. This sort of structure has evolved seperately in several unrelated species, so it's quite reasonable that the long-necked dinos had them. The dinos probably didn't need a large blood supply to the brain, the way a mammal does, so the requirements might not be so bad.

Oh, come on

[Daniel Dvorkin]

It was only 6000 years ago -- didn't anyone get any pictures?

Listen to your mother.

[Anonymous Coward]

Sit up straight! Eat your palm trees! Don't ROAR at your sister! Ignore those tiny furry mousey creatures...they are of no consequenc and won't amount to anything!

Re:Listen to your mother.

[je ne sais quoi]

...I don't care if the neighbors are evolving into birds, we're not doing it. If they were evolving to jump off a cliff, would you do it too? And for the last time, that giant bright spot in the sky the last few days is not an asteroid that will kill us all. I swear, kids these days and their wacky imaginations.

geese

[Red Flayer]

Well, that was a quick slashdotting. Hopefully they'll be back up soon.

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. 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?).

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.

Re:geese

[eldavojohn]

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.

Informed speculation

[MaXintosh]

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

Coiled up on top

[hoggoth]

Come on people, CLEARLY the large long-necked dinosaurs kept their necks curled back and their heads resting on top of their backs.

Re:I'm horny

[mrdoogee]

There's an app for that!