jtr7 on 16/10/2007 at 22:50
Peristaltic pumping in the vessels, and it could raise its tail while lowering its head.:p
Vivian on 16/10/2007 at 23:22
Or an arterial reservoir at the top of it's neck (thats inferring novelty, though. Nothing living has an equivalent). Problem with high systolic pressure would be rupturing blood vessels when the head was held low, but then maybe they could vary it?
Yes, I'm a (phd student) palaeontologist - thing is, I pretty well only work on theropods, so I'm not hugely well informed on sauropods, but they're interesting things to discuss. Ventilation, frinstance - lot of dead air in that neck. They likely had some kind of avian-style air sac system (they have little holes in their vertebrae that are consistent with those that allow lung diverticula to get in in birds), but even so, theres a lot of extra volume to shift with each breath.
Scots Taffer on 16/10/2007 at 23:59
Quote Posted by Vivian
Some goons used up all the hyperbolic names early on, so now they all get saddled with names like futalognkosaurus.
You ever hear about the gay dinosaur they found in the deserts around Austin?
Fagosaurus Tex.
Sinister_Evil on 17/10/2007 at 01:37
@Vivian
what exactly do you mean by cross-section area?
passive support is for standing still mostly. elephants can run at somewhat high speeds for their size 25-30km/h and move around a lot. the same analogy could be made for sauropods. unless the ratio of muscle mass to average force output changes with higher masses. (probably that cross section thing i didnt get).
as for the long neck theory i mean its more relevant cause of what Hewer explained. due to all those problems with a long neck it would be an evolutionary erm.. evolution while the tail is. and the dinos evolved a long neck to balance the long tail.
an ankylosaurs has an arguably shorter tail compaired to body length plus it was shorter compared to its lengh meaning a lower center of mass and thus better ballance. also from a risk point of view it would be worst for a sauropod to fall down during a tail whip than an anky.
crunchy on 17/10/2007 at 01:41
Is it April the 1st already?
Nicker on 17/10/2007 at 05:58
Quote Posted by Vivian
Or an arterial reservoir at the top of it's neck (thats inferring novelty, though. Nothing living has an equivalent). Problem with high systolic pressure would be rupturing blood vessels when the head was held low, but then maybe they could vary it?
Could raising and lowering the tail provide the necessary variance?
N.
- PAGE 2 Boy \0/
Spaztick on 17/10/2007 at 06:08
If there's only one of them that big it sounds more like a freak of nature than a big species.
Vivian on 17/10/2007 at 09:22
Quote Posted by Sinister_Evil
@Vivian
unless the ratio of muscle mass to average force output changes with higher masses. (probably that cross section thing i didnt get).
Bang on. Muscle mass depends on it's volume (length cubed), whereas the amount of force it can produce depends on it's cross section (length squared). If you just scale up a muscle without fundamentally changing it's shape and internal architecture, you get less and less force produced per unit of muscle mass. The same problem applies to bone strength - stress acts upon the cross section, whereas mass is a volume thing.
Quote Posted by Sinister_Evil
as for the long neck theory i mean its more relevant cause of what Hewer explained. due to all those problems with a long neck it would be an evolutionary erm.. evolution while the tail is. and the dinos evolved a long neck to balance the long tail.
an ankylosaurs has an arguably shorter tail compaired to body length plus it was shorter compared to its lengh meaning a lower center of mass and thus better ballance. also from a risk point of view it would be worst for a sauropod to fall down during a tail whip than an anky.
Fair enough, they are different sizes. But because of the relative fragility of huge structures like the tail (same principles as above), I'm not convinced it would make a great weapon. Maybe some fantastic paper has come out that pisses all over me (i'll have a dig around this afternoon), but that sounds like the sort of theory that someone spouts without really considering the kind of mechanical stress such a use would generate in the tailbase, and the kind of power you're talking about having the tail muscles generate. How long would it take to accelerate such a huge mass to such a speed as to make it an effective club? How do you deccelerate it again if you miss? Why not armour it? (actually, I'm pretty sure some did. I'll have to check, again). Why don't you get common fracture pathologies on any of the tail vertebrae?
Quote:
If there's only one of them that big it sounds more like a freak of nature than a big species.
There's the remains of a few this big now. And the vast improbability of being fossilised in the first place makes it overwhelmingly likely that what was fossilied was a typical example of a fairly widespread species. The odds of some lonely freak getting fossilised are kabillions to one.
*Zaccheus* on 17/10/2007 at 10:24
Quote Posted by Vivian
Ventilation, frinstance - lot of dead air in that neck. They likely had some kind of avian-style air sac system (they have little holes in their vertebrae that are consistent with those that allow lung diverticula to get in in birds), but even so, theres a lot of extra volume to shift with each breath.
Another excellent point. I remember reading about the maximum length of a diver's snorkel. Giraffes must have huge lungs!
We don't really have a clue what these things looked like, beyond what can be inferred from their bone structure, do we?
Spaztick on 17/10/2007 at 10:49
I don't suppose it could've been amphibious or lived in the water? I'll tell the truth I haven't actually read the whole article, I just skimmed it, but it seems like a lot of the talk here suggests it has the skeletal structure of a land animal, but maybe it spent most or all of its time in water.
