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Post by tetonbabydoll on Jan 22, 2009 10:35:19 GMT
Ok, here's another one of those just before I sleep questions....
If I follow the current theories correctly, the sauropods held their necks pretty much straight out, and they were not very flexible. If this is true, then how do we explain mamenchisaurus's neck? Surely, a neck that long had to have some movement and use? I was just dozing off and looking at the DOC mamenchi, and wondering.....
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Post by sid on Jan 22, 2009 12:36:29 GMT
The "straight-out sauropod neck theory" is just bullnuts.
Sure,they couldn't twirl their necks like overgrown snakes,but,heck,just take a look at the skeletons and you'll see that they COULD raise their necks easily,not at a 90° degree,granted,but surely enough to eat the leaves of high trees and such...
...And the example of Mamenchisaurus is perfect: how comical would be such a long-necked animal if he could not move his friggin' long neck?! ;D
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Post by [][][]cordylus[][][] on Jan 23, 2009 0:55:38 GMT
Yes, they were much stiffer than once thought. Most sauropods would have been low-grazers, except for brachiosaurs and mamenchisaurs. And those skeletons with the necks raised have most likely been broken to fit into that position.
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Post by tetonbabydoll on Jan 23, 2009 15:05:09 GMT
I know that. Ok, so we have Apatosaurus and Diplodocus doing the low level grazing, Camarasaurus doing middle level, and Brachiosaurus doing high level. So, where does the Mamenchi fit? It had an obsurdly long neck, and its body, does not angle upward like a brachi. So, its neck would be more or less horizontal, so if stiff, what was the point? And I don't see it rearing up so easily either. The DOC mamenchi has some minimal movement, but that is one crazy looking dino.....and the paint around the eyes make it look like it is wearing goggles. I feel a serious Blemishing coming on....
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Post by therizinosaurus on Jan 23, 2009 15:14:54 GMT
Mamenchi lived in China, unlike the other four mentioned.
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Post by sid on Jan 23, 2009 15:28:53 GMT
They were NOT stiff as some people depict them now...Only a crazy would think that
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Post by tetonbabydoll on Jan 23, 2009 15:36:37 GMT
Mamenchi lived in China, unlike the other four mentioned. DUH. Thanks for that... Anyway, I found a sit that has a lot of really, really good shots of the mounted cast. It is amazing, but the neck does indeed have rods in it that would appear to "stiffen" and support it. I don't see how it could even take the pose of the Carnegie one, if that is what the skeleton looked like, CT is right; it would have to have broken or dislocated its bones to do so... What does being Chinese have to do with it? I know it did not live side by side with the other three, that wasn't really my point. Also, according to what I have read, the legs were either even, or even taller in the back, which would have just lowered the neck even more...? Am I reading that right? Here's that link. Some really nice skeletal pics... www.picsearch.com/info.cgi?q=Mamenchisaurus&id=Cvcfqzd5L7Guu2gFrTLspTK2-xSUOBpjZTHrWTyRcuU&start=141
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Post by [][][]cordylus[][][] on Jan 23, 2009 23:42:17 GMT
They were NOT stiff as some people depict them now...Only a crazy would think that .... Says the person who loves old school dinosaurs. ;D Why were they not as stiff? Can you prove to me they were as flexible as you say? ;D
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Post by therizinosaurus on Jan 23, 2009 23:53:54 GMT
Teton, I was just saying that there would be no competition between and Apatosaurus and Mamenchisaurus since they lived on different continents at different times. I think the sauropod diversity of the Morrison is crazy, I don't see how they could have all survived together (granted, they didn't live at exactly the same time, but close enough): Suuwassea (1 species), Diplodocus (4 species), Barosaurus (1 species), Apatosaurus (4 species), Eobrontosaurus (1 species), Amphicoelias (2 species), Supersaurus (1 species), Haplocanthosaurus (2 species), Camarasaurus (4 species), and Brachiosaurus (1 species). Thats an incredible 22 species from 1 formation!
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Post by stoneage on Jan 24, 2009 1:27:49 GMT
I know that. Ok, so we have Apatosaurus and Diplodocus doing the low level grazing, Camarasaurus doing middle level, and Brachiosaurus doing high level. So, where does the Mamenchi fit? It had an obsurdly long neck, and its body, does not angle upward like a brachi. So, its neck would be more or less horizontal, so if stiff, what was the point? And I don't see it rearing up so easily either. The DOC mamenchi has some minimal movement, but that is one crazy looking dino.....and the paint around the eyes make it look like it is wearing goggles. I feel a serious Blemishing coming on.... ;D Teton the problem in part is that there are many types of sauropods. Not all of them held their necks the same way. You have the Diplodocids, the Dicraeosaurids( which had very short necks and very tall spines on their backs), The Rebbachisaurids (which were more or less specialized diplodocidswith wide snouts), The Macronarians (big nosed dinosaurs and forerunners of Brachiosaurids.) , the Brachiosaurids, Titanosaurs (wide bodies,some had armour) the Saltasaurids(wide mouth titanosaurs). The point is there are many different types of sauropods whose necks may have worked in many different ways. There is a lot of disagreement among scientist about this. Primarily it would appear that Diplodocus and Apatosaurus have been the main ones studied. Their necks were compared to the Ostrich and Camel. It's believed that most sauropods could raise their heads at least above their shoulders. ;D
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Post by Tyrannax on Jan 24, 2009 1:35:59 GMT
Brachiosaurids, for example, had to be able to move their necks do at least to some degree.
Why? Animals have to stay hydrated right? Brachiosaurids, like Sauroposeidon, had to bend their necks down, probably being helped out by spreading there legs, to drink.
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Post by bolesey on Jan 24, 2009 2:36:41 GMT
Judging by the long bony processes on some of the neck vertebrae, Sauropd necks probably weren't all that flexible. Though I'm sure it varied, and some were more flexible than others. The next question is how high of an angle did they hold them at. Again, different answers for different sauropods, but I can never understand the point of horizontal necks(as generally depicted for diplodocids and others). I can understand why it suits a giraffe to have a more vertical neck, but horizontal necks? What functional purpose does that serve? If that's what the bones say, that's what the bones say, but it's still a bit of a mystery. The best thing I could come up with was the grass must've always been greener on the other side in those days. (well not grass literally... vegetation, whatever)
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Post by stoneage on Jan 24, 2009 2:41:51 GMT
Brachiosaurids, for example, had to be able to move their necks do at least to some degree. Why? Animals have to stay hydrated right? Brachiosaurids, like Sauroposeidon, had to bend their necks down, probably being helped out by spreading there legs, to drink. ;D I see brachiosaurids kind of moving like giraffes only much bulkier and slow.
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Post by Tyrannax on Jan 24, 2009 2:48:44 GMT
^ Exactly what I was going to add stoneage.
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Post by tetonbabydoll on Jan 24, 2009 5:20:25 GMT
I mentioned the brachio drinking thing in one of my first ever posts. I just have a really tough time envisioning that, though I know they must have done so. If the Kinto brachio is right, the neck is not quite as much of an angle, and I can almost see that.
But, the mamenchi seems to have reinforcing rods, which on the surface would seem to make it a lot less flexible, especially up or down.With shorter front legs, and a slight down slope in the neutral neck position, this animal's head would be very, close to ground level. Fine for eating and drinking, but I would think it would be bad when trying to not get , you know, eaten. If it could not raise that head and neck, would that not make it a very easy target?
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Post by kuni on Jan 24, 2009 6:33:00 GMT
JI can understand why it suits a giraffe to have a more vertical neck, but horizontal necks? What functional purpose does that serve? If that's what the bones say, that's what the bones say, but it's still a bit of a mystery. Sexual selection on long necks, or males with long necks whacking each other with them during mating season would be enough to do it. Then, some specialized groups could take advantage of those long necks to eat high in the canopy or the like.
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Post by [][][]cordylus[][][] on Jan 24, 2009 15:19:49 GMT
Judging by the long bony processes on some of the neck vertebrae, Sauropd necks probably weren't all that flexible. Though I'm sure it varied, and some were more flexible than others. The next question is how high of an angle did they hold them at. Again, different answers for different sauropods, but I can never understand the point of horizontal necks(as generally depicted for diplodocids and others). I can understand why it suits a giraffe to have a more vertical neck, but horizontal necks? What functional purpose does that serve? If that's what the bones say, that's what the bones say, but it's still a bit of a mystery. The best thing I could come up with was the grass must've always been greener on the other side in those days. (well not grass literally... vegetation, whatever) I think I have an answer. Why did diplodocids have long necks? Because they had long tails. Why did they have long tails? To defend themselvles with. Why need to defend yourself? With big fat hungry allosaurs around every corner, well...... (And nobody say "Oh, they dragged their tails all the time" )
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Post by tetonbabydoll on Jan 24, 2009 15:22:48 GMT
MMM, ok, but didn't the mamenchisaurus have superpredators too? Yangchuanosaurus, perhaps? It did not have a whip-like to to defend itself with, and its neck and head look to be almost ground level in a neutral position.
As a point of fact, how complete is the mamenchi's tail?It seems oddly short compared to the neck.....
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Post by [][][]cordylus[][][] on Jan 24, 2009 15:26:05 GMT
^^^ MAybe yangchuanosaurs just didn't prey on them. Although that doesn't make too much sense... Maybe mamenchisaurs had long necks to reach out over the water and eat water plants?
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Post by tetonbabydoll on Jan 24, 2009 15:35:17 GMT
Maybe, put the predation thing bothers me more now....That neck is so vulnerable...would their be a type of raptor contemporary to it too?
Maybe it was poisonous to eat, and was brightly colored, so all predators just left it to wander around peacefully eating its swamp weeds.....hehehe
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