Amargasaurus With a Hump?

[Takama]

I was looking for inspiration on Google for one of a kind models to be made by Jetoar that i will be collecting, and i came across this.



That is a Amargasaurus, notice something different about it?  Its spines is covered in flesh.

Is this a plausible Way to reconstruct this animal?

[stargatedalek]

In some ways it is, in some ways it isn't. The flaps of skin normally seen on Amargasaurus reconstructions are actually highly unlikely and the spines on the neck would have been better off in every way imaginable without them, as just spines. But the spines along the back should be reconstructed like that as opposed to a sail.

[laticauda]

The question is, why are the spines there?  What was there use.  Was it for muscle attachments, storing fat, display, or protection?

[alexeratops]

While the Amargosaurus is turning its neck downwards to eat a fern or low-lying plant, the spines would splay out, protecting the top of its neck from jugular-seeking carnivores, like this:
(image source: Ancient Earth Journal- THE EARLY CREATACEOUS)

Also, if it did have skin between its spines, it could have turned its head down and waved its neck about, showing off flashy colors. Maybe.

[LophoLeeVT]

so it is a high possibility that this pic is part right and part wrong...

[stargatedalek]

so it is a high possibility that this pic is part right and part wrong...

Yes it is, both of these pics actually. The flaps of skin between the spines unless they were very loose and saggy would have stretched uncomfortably when the animal bent down to feed. Whereas if they were loose and saggy they wouldn't have made for as impressive a display (unless perhaps they were very saggy and Amargasaurus swung its head side to side), and would have made good areas for parasites to attach.

[Plasticbeast95]

I'd say that Amargasaurus did not have webbed or fatty neck spines, as this would have restricted neck movement, unless the skin was very stretchy.

[amargasaurus cazaui]

If you place Africa and south America together as they would have been previously, it asks a much larger question perhaps...Amargasaurus, with spines, Ouranosaurus, also with a sail or spined back and even Spinosaurus itself.....all of these animals from a fairly common area with these spinal modifications. These dinosaurs are all unrelated but seemingly share the same geographical origin...could it be that climate was the cause?

[stargatedalek]

I highly doubt it, mainly because these animals were all eating very different kinds of food. Spinosaurus was aquatic and carnivorous, Amargasaurus was a grazer, and Ouranosaurus was a more opportunistic browsing herbivore.

And on that note Ouranosaurus should be depicted with a hump, it's vertebral columns are very broad like a bison and not at all like a Spinosaurus let alone a true sail-back.

[LophoLeeVT]

wow nice pics!

[laticauda]

Thanks for adding the different skeletons, it really highlights the difference between the animals. 

[amargasaurus cazaui]

I am not so sure it is quite as simple as suggested. I do agree the modifications in spinal adornments is different between the three animals. I really do not believe anyone felt they were similar. I still maintain my original point, three seperate animals with distinctly different diets, as mentioned previously, all from the same area with highly modified spinal alterations. I question if environment, something about the climate for that area, or some other common issue they shared helped determine the modifications. What was driving animals from different lifestyles all within the same area to all attain these specific modifications?

[stargatedalek]

The only thing I can think of is that it was a swamp. Perhaps the thicker structure over Ouranosaurus shoulders and Amargasaurus and Spinosaurus hips was used for buoyancy.

[amargasaurus cazaui]

The only thing I can think of is that it was a swamp. Perhaps the thicker structure over Ouranosaurus shoulders and Amargasaurus and Spinosaurus hips was used for buoyancy.

Or taking it a  step further how about a huge Mangrove....

[LophoLeeVT]

well it is highly douldtly.
at the age of spinosaurus there were huge swamps.

[stargatedalek]

I was sort-of lumping mangrove under swamp. Correct me if I'm wrong but IIRC swamps are bodies of water covered by trees overhead.

[amargasaurus cazaui]

Actually what I was getting at , was in the book "Lost Dinosaurs of Egypt" one of the things the author does is determine based on the large amounts of material that appears to be roots and vines fossilized at the location where they discover the sauropod, that the area was a mangrove. He was of course working with a group that was retracing Stromer's steps, the man who discovered Spinosaurus in Egypt. He determined the area was a mangrove....so we can be fairly certain that is what the environment for that animal at least was.
    As for the difference in swamps and mangroves, I read in wiki that by nature mangroves are associated with saline water....whereas I am guessing but would assume a swamp could or would generally be more of a freshwater type location, although perhaps not necessarily.....

[Newt]

Mangroves are a distinct subset of swamps. Either way, though, forested wetlands are relatively shallow (except during floods), and animals of the sizes we are discussing here would not need to be buoyant. I spend as much time in swamps as I can manage, and I can assure you that by the time even a relatively dinky animal such as myself needs to worry about buoyancy, the forested area has already been left behind. This has to do with the nature of plants; a tree seedling cannot get started in deep dirty water.

Now, some swamps and mangroves are adjacent to deeper channels, and you could posit an animal that needs to be buoyant to get from one such habitat to another - but I find myself pretty dubious that dorsal floats would be much use to such animals. They're already lighter than water (except Spinosaurus, which has gone to a great deal of trouble to make itself dense enough to dive, so why spoil that with a float?) and can probably swim, or at least float, just fine when necessary - just like pretty much every modern large land animal.

[stargatedalek]

We also have immense fish so I think it's fair to say either these trees were adjacent/among to a vast network of deeper channels.

Perhaps Ouranosaurus and Amargasaurus often ran the risk of becoming trapped by dense tree's as tides rose which could make a buoyancy device a very useful mechanism to escape. For Spinosaurus however, if I had to guess the structure over its hips was for balance, it's thicker than the one over its shoulders and could well have helped offset those tiny legs. As for the structure on the front segment of Spinosaurus however I have no single best guess.

[Newt]

Or....those fish are preserved in the swamps because they died there after being stranded by receding floodwaters, not because they habitually lived there. The same could be said for the dinosaurs themselves. Big animals and dense swamps are not the best combination. If a big animal is going to hang out in such a habitat it needs to be either very maneuverable (crocs) so it can go around the vegetation, or very powerful (elephants) so it can move the vegetation out of its way. Carrying a giant sail on your back is counterproductive in either scenario.

I really think you're going down a blind alley here. Also, as you yourself pointed out, these three animals have very different anatomies of their elongated vertebral spines; there's no particular reason to think that they're all doing the same things with them.