Spinosaurus new look!

[stargatedalek]

aegisuchus (along with stomatosuchus) has a skull that I think suited it best for;
-digging in soft substrate
-sucking in schools of small prey, almost like a whale

[darylj]

It certainly did exist. I just can't...ya know, imagine it...moving and hunting etc.
The black heron technique is actually a great idea as tobwhat spinosaurus may have used it's sail for, and actualy gives to a quite plausible reason as to why this sail grew so large... Bigger sail - more food - bigger animal - bigger sail - more chance of attracting a mate.
Hey, I know that's a very basic evolution layout, but I'm writing on my phone so bare with me.

I like that idea, it has real promise.

As for buoyancy etc. I don't know to much about why fish, dolphins etc have fins / flukes... Could there be a link??

Also is it now assumed that the sail was a sail? And not a hump???

[darylj]

Sorry, i missed an entire page. Ignore the hump / sail comment. And sorry to double post.

[HD-man]

Jura's "Tall spines and sailed backs: A survey of sailbacks across time" article is especially relevant to this thread: http://reptilis.net/2014/06/21/tall-spines-and-sailed-backs-a-survey-of-sailbacks-across-time/

[Balaur]

On Spinosaurus locomotion, I think that it's a facultative biped. Because it lived much of its life in the water, I suspect that it mainly walked on its knuckles, but that its time on land would be restricted as to not damage the knuckles. However, if it saw something or wanted a quicker escape, I believe it could walk on two legs, rearing up, like a penguin, and waddle. However, I don't think it is even capable of running. In addition, I do think it also could belly slide, being on its belly, and use its legs to push itself forward, also like a penguin. Basically, I don't think it had a set way to move on land, but just used whatever it could to move on land. It really doesn't matter, because it spent so much time in the water.

[Seijun]

What about the points raised by Haedden? Were these ever addressed?

http://qilong.wordpress.com/2014/09/12/the-outlaw-spino-saurus/

-Shoulder blades not properly positioned for quadruped locomotion
-Presence of a furcula severely hindering quadruped locomotion
-Forelimbs lacking any adaptations for quadruped locomotion

[stargatedalek]

I don't really see any need for it to be quadrupedal,  perhaps it could have used its arms to forage or pull itself along the bottom of water bodies, but thats the closest I can picture being functional

[Dinoguy2]

What about the points raised by Haedden? Were these ever addressed?

http://qilong.wordpress.com/2014/09/12/the-outlaw-spino-saurus/

-Shoulder blades not properly positioned for quadruped locomotion
-Presence of a furcula severely hindering quadruped locomotion
-Forelimbs lacking any adaptations for quadruped locomotion

Yeah I don't think many people think it was quadrupedal, but surely it wouldn't have been a great biped either. I doubt it came fully on to land much at all, personally. But when it did it could probably walk very awkwardly.

[DC]

National Geographic Oct issue is out.  The Spino article is not long or real detailed but covers the main points people have raised in the thread.  The is some nice art work by Bonadonna that gives the look and feel of the reconstruction.

[darylj]

Yeah i can't see it a quadruped in anyway.

Perhaps it only came on land to lay eggs!?

[amargasaurus cazaui]

Yeah i can't see it a quadruped in anyway.

Perhaps it only came on land to lay eggs!?

lol while we are redoing it entirely who said it laid eggs?

[darylj]

Haha that is true. But if we are sold on it using its sail to keep warm, then I'm sticking with an egg laying creature.
Using its claws to dig a borrow then belly sliding back to water.

[Balaur]

Why would the sail mean it is an egg laying animal? I personally think it is an egg laying animal becausw so far there are no known viviparous archosaurs.

In defense of the authors position that it is a quadruped, certain animals don't have adaptations for doing something. For instance, goats can climb trees and browse, but there is nothing in its skeleton to suggest it could, yet they do. The quadruped thing could be something that has recently evolved in Spinosaurus. This gets to how it got out of the water. I doubt the thing could actually walk on two legs when getting out, as the slippery mud would mean it would topple over. At the very least, it walked on four legs getting out of the water. However, the abscence of adaptations doesn't always mean it didn't do something. As another example, crocodile can climb trees, but there is nothing in the skeleton to show it could. I actually have trouble seeing it as a quadruped or a biped, but I don't see a proboem with it being both. Personally, I think that it almost never came on land. Maybe like whales they "slept" in the water, only coming ashore to lay eggs. Also, what about the babies? I'm thinking that they were fully quadrupedal, and depending if it is a small size, it could walk efficiently on land on four legs.

In the end, Spinosaurus is a very strange dinosaur, probably about as weird or even weirder than Deinocheirus. What we basicslly have is an animal that is part Ouranosaurus (the sail), part crocodile, part Baryonyx, part loon, and part whale. I've always had the idea that some non-avian dinosaurs were aquatic, I mean, looking at birds, why would they be restricted to the land? Also, a monograph of Spinosaurus is coming soon, so probably once that comes out we can make our minds up.

[Seijun]

Hmm... I don't think it is the same as comparing to a goat. Hooves don't seem like they would be very good for climbing or rock jumping, but there is nothing about the anatomy of a goat that would suggest it to be physically impossible, either. With spinosaurus, the issues raised seem to be that quadruped locomotion would have been physically impossible given what we know about the anatomy of the front limbs. At least, this is what is being claimed.

[Ultimatedinoking]

Hi everyone, I'm back! 

[stoneage]

People are questioning how a fully aquatic spino could compete with "super crocs" but which super crocs lived inhe same time and place? Sarcosuchus is several million years older and lived alongside Suchomimus, not Spinosaurus. Many species of smaller crocs lived alongside Spino and yet somehow they managed not to all kill each other off.

Arguments like this seem to rely on the fallacy of the Mesozoic as a life or death struggle of constantly warring monsters when in reality animals can have subtle niche partitioning not necessarily obvious from anatomy alone, and that predators tend to avoid conflict wih each other whenever possible.

The large size of adult spino alone may have been enoughto deter attack from carchs, much like sauropods. I'm not saying the ungainly Spinosaurus never got killed by more agile carnosaurs, just that it may have been rare enough to not have had a major impact or as everyone optionally pressure.

He fact is the bloggers were wrong and have admitted such public ally, the published proportions are right, and we just need a hypothesis to explain how spino actually lived. I personally don't agree it was a quadruped, I think it could have walked pangolin or Godzilla style just fine on two legs. But it would have been relatively awkward on land and certainly was not capable of running.

How do you know that Crocs didn't kill off Spino or that Spino didn't kill off Crocs.  You don't see any of them around do you.  If they had similiar prey then one or the other could have been more successful eventually leading to the extinction of the other.

[Lythronax]

... This gets to how it got out of the water. I doubt the thing could actually walk on two legs when getting out, as the slippery mud would mean it would topple over. At the very least, it walked on four legs getting out of the water...

Before, I uploaded a drawing of a trail that is known to belong to a bib theropod (Theroplantigrada encisensis). The trail indicates that the animal was going out of the water through a muddy substrate, with bipedal plantigrade locomotion. At the beginning, the animal performs short steps with the legs wide apart, then the steps become longer and the trail becomes narrower as the animal moves away from the water. The trail shows no marks of arms, belly or tail.

When it comes to going into the water, I'm not saying that the animal could not glide, as gliding saves energy.

[darylj]

Boring day at work.. and couldn't get this thread out of my mind... resulted in this....



just an idea...
Also, looking at the jaw bones, could it possibly have had a head more like a dolphin than a crocodile??

and, i guess i just thought, if a creature has developed the ability to warm itself.. then giving birth to live young is quite a feat.
i dont know why i thought that... but yeah.. sail... not fully warm blooded... egg laying.

[Concavenator]

My own interpretation
http://5aurophaganax.deviantart.com/art/New-Spinosaurus-485974024

[darylj]

Nice interpretation