New Spinosaurus Restoration!

[suspsy]

Yeah, jaguars use a very specific strategy when it comes to hunting caimans: they generally either swim up to them very slowly and quietly while they're basking, or they leap from the riverbank into the water and land right on top of the caiman. And they know precisely where to bite the caiman on the back of the skull so that it can't bite the jaguar back and dies fairly quickly. A Carcharodontosaurus simply wouldn't have the speed, the agility, or the intelligence to pull off such a surgical strike.

[Dilopho]

Yeah, jaguars use a very specific strategy when it comes to hunting caimans: they generally either swim up to them very slowly and quietly while they're basking, or they leap from the riverbank into the water and land right on top of the caiman. And they know precisely where to bite the caiman on the back of the skull so that it can't bite the jaguar back and dies fairly quickly. A Carcharodontosaurus simply wouldn't have the speed, the agility, or the intelligence to pull off such a surgical strike.

Not to mention, Jaguars are fast and can swim well. If you're hunting something like a crocodile, caiman, Spinosaurus....you want to be absolutely sure you can do well in the water, because they are built to be unbeatable in it.

I can't imagine it going well for Carcharodontosaurus if it falls into a river with a spinosaur. There's no way it's a good swimmer, or at least not enough to escape fast enough.

[Sim]

If I'm remembering right, theropods would've generally been good swimmers.  I don't think Carcharodontosaurus would usually prey on Spinosaurus though, it doesn't seem built for that.  It seems built for feeding on plant-eating dinosaurs.

[Concavenator]

And that's assuming Spinosaurus wasn't marine, which considering most of the fossils are of young (including several very young) animals and they come from coast adjacent mangrove swamps I think is extremely likely. Adults probably lived in the ocean, returning to shore to leave the young in protected estuaries. More like sharks or puffins than crocodiles.

Wow, that idea is fascinating indeed! What an interesting evolution Spinosaurus has had. It began with the concept of it being a "sail backed allosaur" and now we're discussing it it was or not marine   Makes me wonder what would have happened if spinosaurids had kept evolving. Perhaps they would have became animals similar to whales. Spinosaurus itself reminds me of Rodhocetus.

I can't imagine it going well for Carcharodontosaurus if it falls into a river with a spinosaur.

The thing is that I don't think the Spinosaurus would kill it and feed on it, I don't know. It was very clearly adapted for eating fish.Even if Carcharodontosaurus was clumsy on water, I have a hard time envisioning the Spinosaurus, who was used to eating smaller fish than itself suddenly taking on a ginormous 14 meter sized theropod (and a predator at that, it's not like it was a therizinosaurid or a deinocheirid)

[HD-man]

@ITdactyl

with big individuals (male carch?)

Probably female

@Narutoceratops

Wow, that idea is fascinating indeed! What an interesting evolution Spinosaurus has had. It began with the concept of it being a "sail backed allosaur" and now we're discussing it it was or not marine   Makes me wonder what would have happened if spinosaurids had kept evolving. Perhaps they would have became animals similar to whales. Spinosaurus itself reminds me of Rodhocetus.

I wouldn't get too excited about the idea of fully-marine, live-bearing Spinosaurus (which is about on par w/the elephant seal idea: http://dinotoyblog.com/forum/index.php?topic=1960.0 ). Last I checked, no one is seriously discussing said idea in the scientific literature (In fact, see "Posture and balance": https://markwitton-com.blogspot.com/2020/05/spinosaurus-2020-thoughts-for-artists.html ).

[Concavenator]

I wouldn't get too excited about the idea of fully-marine, live-bearing Spinosaurus (which is about on par w/the elephant seal idea: http://dinotoyblog.com/forum/index.php?topic=1960.0 ). Last I checked, no one is seriously discussing said idea in the scientific literature (In fact, see "Posture and balance": https://markwitton-com.blogspot.com/2020/05/spinosaurus-2020-thoughts-for-artists.html ).

Yes, it's certainly difficult for me to imagine a completely marine Spinosaurus, as if it was a whale. But just that (speculative) idea results very interesting, that's what I was trying to say.
Oh, and that Mark Witton's post is very interesting, though for some reason his interpretation of Spinosaurus purposedly keeps the old sail, rather than the new (2014) one. 

[suspsy]

I wouldn't get too excited about the idea of fully-marine, live-bearing Spinosaurus (which is about on par w/the elephant seal idea: http://dinotoyblog.com/forum/index.php?topic=1960.0 ). Last I checked, no one is seriously discussing said idea in the scientific literature (In fact, see "Posture and balance": https://markwitton-com.blogspot.com/2020/05/spinosaurus-2020-thoughts-for-artists.html ).

Already shared Witton's blog post on the previous page.

[HD-man]

Oh, and that Mark Witton's post is very interesting,

I concur. I know it was posted on page 4, but figured you & others just joining this thread might not have seen it.

though for some reason his interpretation of Spinosaurus purposedly keeps the old sail, rather than the new (2014) one. 

Did you read Witton's post in its entirety? He explicitly explains his reasoning.

[Concavenator]

H @HD-man got it, I see it now. I was just surprised to see that sail shape again, ever since the 2014 Spino, I have never seen that sail shape on any reconstruction that pretended to be accurate.

[ITdactyl]

Jaguar hunting caiman is just such an interesting modern phenomenon, it's easy to get similar fanciful ideas when thinking of the giant theropods.

And it seems the fancy hit Luis Rey too.


https://luisvrey.wordpress.com/2020/10/10/and-now-for-the-spinosaurus-apotheosis-downfall/

Granted, he does acknowledge that it is just a fanciful idea.

[Tyto_Theropod]

I'm necromancing here, but reading over this thread made me think up my 'personal canon', informed by a biology degree, wildlife documentaries, and a lot of birdwatching, of a situation where Carcharodontosaurus fell into a Spinosaurus-infested river...

Carcharodontosaurus (possibly looking for something to scavenge along the shoreline/riverbank): *Loses its footing and falls into the water.*

Birds: *Scatter, making a noise.*

Spinosaurus: *Is surprised by all the commotion and looks up, deciding whether it should be afraid or not.*

Carcharodontosaurus: *Thrashes about and eventually makes its way out of the water.  Leaves, trying to restore its battered dignity and pretend nothing happened.*

Spinosaurus: *Continues with what it was doing beforehand, perhaps wondering what all that was about.*

Sometimes wild animals are brutal, but it's important to remember that in real life encounters are often pretty anticlimactic and even funny...

And then I went off on a train of speculative thought...

If the Carcharodontosaurus was injured or ill (either as the cause or the result of the fall), or got into really serious trouble in the water, and there were multiple Spinosaurus, I suppose they might seize the opportunity of a meal and 'mob' it, but that's more opportunism than a calculated attack.  Conversely, I'd imagine a Spinosaurus on land might be vulnerable to a predation by one or more Carcharodontosaurus if it didn't get to water fast enough.  There'd be a better chance of dinner for the Carcharontosaur(s) if the Spinosaurus wasn't fully grown and was still smaller than them.  Also, short-legged aquatic animals like crocodiles, otters and seals (and that very much includes 'true' seals, i.e. Phocidae) can be surprisingly fast on land.  If Spinosaurus was the same, it might again come down to a scenario with an individual in poor physical shaped being mobbed by multiple Carcharodontosaurus.  In either case, I doubt a healthy adult of one species would go after a healthy adult of the other.

TL;DR: I think there are theoretically ways in which a Carcharodontosaurus could kill a Spinosaurus and vice versa, but they aren't very like the jaguar and crocodile idea.

[andrewsaurus rex]

Where does the sail shape for Spinosaurus come from?  As far as I know it's pure speculation and based on the fin of the sailfish, for some reason.  With only bits and pieces of Spinosaurus sail vertebrae found, it's a big leap to the double hump shape that has become pretty much the standard for Spinosaurus reconstructions.

And same question for the big gullet/throat that Spinsoaurus is commonly being illustrated with.  What evidence is there for that?

[stargatedalek]

Where does the sail shape for Spinosaurus come from?  As far as I know it's pure speculation and based on the fin of the sailfish, for some reason.  With only bits and pieces of Spinosaurus sail vertebrae found, it's a big leap to the double hump shape that has become pretty much the standard for Spinosaurus reconstructions.

And same question for the big gullet/throat that Spinsoaurus is commonly being illustrated with.  What evidence is there for that?

What rock have you been hiding under for the past six years mate?

There is actually quite a decent amount of Spinosaurus vertebrae material now known.

[Sim]

Apparently Spinosaurus's sail shape is unknown.  Scott Hartman made a blog post about this here: https://www.skeletaldrawing.com/home/the-road-to-spinosaurus-ii-known-unknowns11252020

[andrewsaurus rex]

I didn't mean to imply the gullet was made up, I was just curious as to what evidence there was for it.  Perhaps something I hadn't heard about.  Much of paleontology is based on reasonable speculation, so I have no problem with it.

As to the sail, very little is known unless something was discovered very recently and as far as i'm concerned the shape of the sail is pure fantasy.  Even Dr. Hartman's restoration is a bit on the generous side given the actual amount of recovered material and its condition.

As far as I know the sail shape was simply based on the sailfish, at some point, for some reason, and caught on because it looked cool.  All that can be said with certainty is that it was tall at the very front.

There's been lots discovered in the last few years, about the back legs and tailfin, but virtually nothing about the sail, that I've read about. Of course the light isn't great here, under my rock...