Spinosaurus new look!

[Dobber]

Dinomike, sorry if I missed it but is your swimming Spino a one off or kit It is amazing!

Chris

[Stuckasaurus (Dino Dad Reviews)]

I was looking around at Safari's catalog recently, and the thought occurred to me that their orange Spinosaurus model accidentally preempted the basic look of the "new Spinosaurus", what with the sail shape and the quadrupedal stance.

[Simon]

Here's an update from a recent article in the news:

http://www.theatlantic.com/science/archive/2016/03/saga-of-the-spinosaurus/476286/

[Blade-of-the-Moon]

The image of the guy walking by and ignoring Spino skeleton is a bit depressing..as is the fact the reconstruction was the centerpiece of an exhibit only a short while ago.  Kind of like the Rex eating a goat in JW and the kid ignoring it to talk on his cellphone, a remainder that whats new and cool today will be gone tomorrow.

[SpartanSquat]

Well from what I read...the material is probably from another genera, more specifically Sigilmassasaurus. So the new look is still debatable and the scientist usually make mistakes, remember the Brontosaurus with Camarasaurus skull.

[stargatedalek]

Well from what I read...the material is probably from another genera, more specifically Sigilmassasaurus. So the new look is still debatable and the scientist usually make mistakes, remember the Brontosaurus with Camarasaurus skull.

Spinosaurus and Sigilmassasaurus are so similar that even if they are different genera it's silly to say they were different enough to make the long limbed Spinosaurus plausible again. Sigilmassasaurus has the small limbs first attributed to Spinosaurus aegyptiacus, but basing Spinosaurus legs on a distant relative like Suchomimus or Baryonyx instead of the very close Sigilmassasaurus is like saying it's fair to speculate a twin will look like their great great great grandparent instead of like their other twin.

[Halichoeres]

Well from what I read...the material is probably from another genera, more specifically Sigilmassasaurus. So the new look is still debatable and the scientist usually make mistakes, remember the Brontosaurus with Camarasaurus skull.

Spinosaurus and Sigilmassasaurus are so similar that even if they are different genera it's silly to say they were different enough to make the long limbed Spinosaurus plausible again. Sigilmassasaurus has the small limbs first attributed to Spinosaurus aegyptiacus, but basing Spinosaurus legs on a distant relative like Suchomimus or Baryonyx instead of the very close Sigilmassasaurus is like saying it's fair to speculate a twin will look like their great great great grandparent instead of like their other twin.

I dunno, the closest relative of the bush dog is the maned wolf (less than 5 million years' divergence), and together they have a greater disparity in leg length than basically the rest of the dog family combined. Given how very odd the Ibrahim et al. Spinosaurus reconstruction is relative to all other theropods, I don't think it's possible to say which is the more parsimonious interpretation yet.

[Sim]

Good points Halichoeres!  Also, Spinosaurus and Sigilmassasaurus are both known only from very fragmentary remains.  A lot of their skeleton is unknown, and just how similar and closely related they are to each other is unknown.  I won't be surprised if Spinosaurus does have short legs, but I think Spinosaurus, Sigilmassasaurus or any other theropod being a quadruped is almost certainly incorrect.  Right now there isn't any reason to think any theropod would have been a quadruped.

The appearance of the torso of Spinosaurus (and Sigilmassasaurus) isn't known, so I wonder why the 2014 quadrupedal Spinosaurus reconstruction has this part of the body so long.  I imagine the long torso in conjunction with the short legs is what made many people think Spinosaurus would've been quadrupedal, or that it couldn't leave water, or that it had to slide along in mud, or... that it had any of the other very odd postures/lifestyles that have been suggested for it.  However, as far as I know, the long torso is nothing more than baseless speculation..  If Spinosaurus/Sigilmassasaurus had short legs, I wonder if it also had a short torso...

[amargasaurus cazaui]

Something to remember in the discussion...Stromer himself, felt he had discovered two seperate species of Spinosaurs with the material he had. He referred to them as Spinosaurus A and Spinosaurus B, and he also named multiple crocodilyforms from that same material, many of which have not proven out over time. Makes you wonder just what he did and did NOT have ...

[stargatedalek]

Regardless of the validity of the remains themselves the reconstruction that came coupled with them is fatally flawed. It's very shrinkwrapped to the point that the shrinkwrapping actually throws off their balance estimates. I mean look at the poor things sail it's a damn spiderweb, that's gotta be painful.



Compare the actual skeleton:



If you follow the thickness of the individual vertebrae columns they get thicker further towards the back. The ones directly over and behind the hips are actually very broad. This coupled with the unusual dip makes me think we're looking at a structure (perhaps even two structures) that was thinner near the front and thickened over the hips. This sort of thing could definitely have served to balance a bipedal Spinosaurus with these proportions.

[alexeratops]

If you follow the thickness of the individual vertebrae columns they get thicker further towards the back. The ones directly over and behind the hips are actually very broad. This coupled with the unusual dip makes me think we're looking at a structure (perhaps even two structures) that was thinner near the front and thickened over the hips. This sort of thing could definitely have served to balance a bipedal Spinosaurus with these proportions.

That is actually a really good point I never thought about. Of course there could be a hump as previously presumed, but having it actually serve a balance-related purpose is something that never crossed my mind. Good job.

[MLMjp]

If you follow the thickness of the individual vertebrae columns they get thicker further towards the back. The ones directly over and behind the hips are actually very broad. This coupled with the unusual dip makes me think we're looking at a structure (perhaps even two structures) that was thinner near the front and thickened over the hips. This sort of thing could definitely have served to balance a bipedal Spinosaurus with these proportions.

That's actually a very nice theory stargate! It seems very plausible.Wonder what other members with more knowlegde about this think of your idea.

[Mamasaurus]

I thought that the movie of the pangolin embedded in the article also illustrated an interesting point. 

Keeping in mind how broad the posterior spines are, and how long the tail seems to be- not to mention no evidence for weight-bearing forelimbs- I find that a bipedal stance wouldn't be an issue for spinosaurus. The thought of a pangolin or pelican type waddle is quite endearing  wouldn't it be interesting if spinosaurus was a tail-dragger? 

[Kovu]

Personally, I think this method of terrestrial locomotion makes the most sense:
http://antediluviansalad.blogspot.com/2014/09/last-man-standing-el-ultimo-hombre-as.html

And this for aquatic:
http://antediluviansalad.blogspot.com/2015/10/spinosaurus-unauthorized-i-hippos-are.html
http://antediluviansalad.blogspot.com/2015/11/spinosaurus-unauthorized-ii-spino.html
http://antediluviansalad.blogspot.com/2016/03/spinosaurus-unauthorized-iii-run-spino.html

He brings up some excellent points! I can 100% see Spinosaurus as a clumsy loon-esque-like creature on land and a giant predatory hippo in the water. Looking at the biomechanical and environmental evidence, it makes sense...

[Blade-of-the-Moon]

I've always loved the loon concept..makes a lot of sense to me.

[FishFossil]

I've always loved the loon concept..makes a lot of sense to me.

If Spinosaurus was indeed utilizing a loon-like style of locomotion, that would mean it is an almost entirely aquatic animal. Coming on land can cause severe injuries for loons, and zoos actually have to put them on pilllows so as to prevent them from injuring themselves. And with an animal as large as Spinosaurus I can only imagine how much more severe injury to the stomach would be. I personally think a pangolin style of movement is more likely.

[Blade-of-the-Moon]

Loons in the wild manage it I suppose.  I could see it coming on land only to lay eggs and then guarding the nest from the water.  Just like a bird/crocodile.    Though I'm not saying it was definitely that way, I think more loon-like in the water , but it could certainly been otherwise.   From all the new evidence I see an animal that is trying very hard to be mostly aquatic.   Oddly enough the only thing not making sense is that sail.  What on earth did it need it for?  There are a few species of fish like Marlin with sails but I can't see Spinosaurus needing it in the same way.

[Halichoeres]

The sticking point for me when I try to imagine this version of Spinosaurus trying to move around on land is how large it is. Both loons and pangolins are under a few kilograms. If a loon can hurt itself on land, as FishFossil says, then imagine how badly an animal weighing a few tons would be injured by stumbling. Mass (and therefore force of impact) goes as the cube of length, which is to say, the larger they are the harder they fall. Something that large has to either be very thoroughly aquatic or competent on land (hippos are competent on land, for example). Maybe a bunch of muscular levers originating on the neural spines like stargatedalek postulated a while back could help it move around on land, although it seems like an awful lot of energetic expense to invest in balance. I mean, what would be the function of that, standing at water's edge like a (construction) crane and gleaning things near the surface?

[HD-man]

Personally, I think this method of terrestrial locomotion makes the most sense:
http://antediluviansalad.blogspot.com/2014/09/last-man-standing-el-ultimo-hombre-as.html

And this for aquatic:
http://antediluviansalad.blogspot.com/2015/10/spinosaurus-unauthorized-i-hippos-are.html
http://antediluviansalad.blogspot.com/2015/11/spinosaurus-unauthorized-ii-spino.html
http://antediluviansalad.blogspot.com/2016/03/spinosaurus-unauthorized-iii-run-spino.html

He brings up some excellent points! I can 100% see Spinosaurus as a clumsy loon-esque-like creature on land and a giant predatory hippo in the water. Looking at the biomechanical and environmental evidence, it makes sense...

I've always loved the loon concept..makes a lot of sense to me.

Actually, as indicated by the Hartman quote, belly-sliding doesn't make sense for Spinosaurus.

Quoting Hartman ( http://www.skeletaldrawing.com/home/there-may-be-more-fishiness-in-spinosaurus9132014#comment-1594913312 ):

Belly sliding requires you to be able to propel yourself on the substrate. Crocodilians are already built for this with their sprawling limbs. Loons and (especially) penguins have shifted their legs posteriorly and rotated the acetabulum laterally so their limbs push out to the side more (loons of course depend on that as a propulsive stroke). So short legs aren't enough, Spinosaurus would need to be shown to have a radically modified pelvis, which the neotype simply doesn't have. Also note that plenty of living theropods simply walk along tidal flats - loons belly slide not because walking can't be done, but because their aquatic adaptations make locomotion on land difficult.

Now, if those pelvic and femoral adaptations were there in Spinosaurus I would say it deserves more exploration, but without them its hard to see how belly-sliding could have been more than a very occasional mode of locomotion. Second, there seems to be no reason to invoke it - matching the skeleton to the published element lengths makes normal theropod bipedality easy to accomplish, and it also moves the center of mass back. With those two problems solved belly sliding as a regular form of locomotion becomes a solution in search of a non-existent question.

I understand the appeal of breaking false dichotomies, but sometimes dichotomies aren't false, and sometime the data simply doesn't demand it.

[Kovu]

Forgive me if I'm mistaken, but isn't Hartman's reasoning dependent on whether you agree with him about the limb proportions?
The point about the acetabulum does throw a wrench in the loon idea though.

But... wouldn't all this also be dependent on how aquatic Spinosaurus was?