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

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: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:Two Things

[techess]

I agree until we get a better idea of the soft tissue we won't really know.

Giraffes have a very cool way of improving their circulation without just throwing a bigger heart at the solution:
http://news.softpedia.com/news/Some-Weird-Giraffe-Issues-80555.shtml

"To pump the blood high to the brain, the heart of the giraffe is very large: up to 11 kg (25 pounds). The heart pushes 60 liters of blood per minute. The muscles of the neck arteries are relaxed with each heart beat, helping the propulsion of the blood to the brain. In the neck veins, special valves impede the blood to flow back too rapidly, meanwhile preventing the emergence of a syncope (fainting due to sudden lowering of the blood pressure). At the base of the feet, where pressure is low, there is a system of capillary vessels like in humans, impeding the appearance of edemas. Like humans, the giraffe is one of the few vertebrates which is taller than longer, and NASA studied blood circulation in giraffes for creating an anti-gravity garment for astronauts."

Also horses while not having an extremely long neck also deal with circulation problems by more than throwing in a bigger heart.
http://en.wikipedia.org/wiki/Circulatory_system_of_the_horse
The frog
Each hoof contains a structural component known as the "frog," which covers the deeper structure of the hoof known as the digital cushion, a vessel-filled tissue. When the horse places weight on a leg, the ground pushes upward on the frog, compressing it and the underlying digital cushion. This results in squeezing blood out of the digital cushion, which then helps to pump it back up the leg, helping the heart to work against gravity.

Nature has done some amazing and unique things with soft tissue to get around limitations. It would be so interesting to find out how dinosaurs worked and what their bodies were really like.

Re:TFA Is slashdotted

[Binestar]

http://www.unmuseum.org/dinobront.htm

Today, scientist's vision of the habits and habitat of the Apatosaurus are quite different than what Marsh and other early paleontologists had thought. Early analysis suggested that the animals must have been weak because their small heads could only chew the minimum amount of food necessary to fuel such a big body. So weak, in fact, that large sauropods were thought to be slow, unable to lift their bulky tails off the ground and only able to support their massive weight by living in shallow lakes and swamps where water floated their bulk.

Paleontologists like Bakker showed that this image was wrong. No Apatosaurus skeleton has been found in an ancient body of water and its feet were not at all suited for walking through marshy and muddy ground. In fact, Bakker notes in his book Dinosaur Heresies, an analysis of changes in geology over time suggest that large sauropods moved out of areas as they became wet: they didn't like swamps at all.