Spinosaurus new look!

[DC]

"I could see a Carcharodontosaurus killing a Deltadromeus,but I wouldn't see a Carcharodontosaurus killing a Spinosaurus,or viceversa."  I think it's entirely possible especially if Carcharodontosaurus hunted in groups as some scientists suggest. that video with the lions attacking the crocodile is a perfect example.

I agree with you assessment.   The adult top predators would have avoid each other.  Deltadromeus would be pretty fast and based on the old Strohmer fossil larger .  I suspect hatchlings and young spinosaurs would have been a nice meal for all the various theropods and most of the croc forms.  On land a group of Carcharodontosaurus would have been dangerous for even an adult.  It would make a great diorama.

[HD-man]

How do you figure that? As others here have pointed out, the proportions of the reconstruction don't match the measurements from the paper & the forelimbs are incompatible with quadrupedal walking. Last I checked, that IS the current evidence. As for the authors' response, IDT they really said anything ("I do think that parts of their response utilize an argument from authority in place of providing data. Of course with other papers in progress there may be limits to what can be shared without compromising their ability to publish it. While that is an understandable position to be in, I naturally find those parts to be unpersuasive, and in particular I remain unconvinced that they have properly scaled the hind limbs and pelvis (elsewhere Mark Witton has already anticipated part of why that is)": http://www.skeletaldrawing.com/home/aquatic-spinosaurus-the-authors-responsd9182014 ).

The bolded part of the above quote refers to Witton's "The 'Spinosaurus reboot': sailing in stormy waters" article ( http://markwitton-com.blogspot.com/2014/09/the-spinosaurus-reboot-sailing-in.html ). The following quote & pic are especially relevant as an "independent test of the alleged hindlimb proportion issues in the new-look Spinosaurus."

Quoting Witton ( http://markwitton-com.blogspot.com/2014/09/the-spinosaurus-reboot-sailing-in.html ):

One thing is clear a week after the 'Spinosaurus reboot' (a phrase coined by Mickey Mortimer) was revealed amidst a furore of academic and media swirl: Spinosaurus c. 2014 has not met the warmest reception from the palaeontological community. A sceptical tone, sometimes very openly so, can be seen in numerous articles from the first popular science write-ups to articles penned by professional palaeontologists. As we all know by now, the primary concerns centre around Ibrahim et al.'s (2014) new Spinosaurus aegyptiacus reconstruction, which Brian Switek describes as a 'hodgepodge [of] different dinosaurs... the new subadult skeleton, digital representations of the original and long-lost Spinosaurus bones, vertebrae and hands that may or may not belong to Spinosaurus, as well as replacement parts from an assortment of spinosaurs'. Allegations have been made that scaling errors are responsible for the unusual new bauplan rather than an unprecedented lifestyle, with the allegedly tiny legs being far more proportionate once the scaling problem is addressed. These undermine the credibility of the furthest reaching claims of the authors - theropod quadrupedality and a lifestyle/locomotory strategy akin to early whales. Two widely shared and commented blog articles on this topic over at Scott Hartman's Skeletaldrawing.com have cast enough doubt over the new reconstruction that the Spinosaurus 2014 authors publicly responded to the criticism, but the reply is really just a holding message. Other than pointing out well known problems of measuring images rather than fossils (which, to be honest, are unlikely to produce the large scaling problems levelled at the paper), the message is essentially 'all will be clear in an upcoming Spinosaurus monograph'*.

*For what it's worth, I took five minutes to measure up the new Spinosaurus skeletal restoration myself following Nizar Ibrahim's measuring instructions for dorsal vertebra 8, just to see if I could make head-or-tail of the debate. Differences in measuring landmarks were chalked up as being a potential problem, so I measured the ilium and femur blind to other methods, instead using whatever landmarks were most intuitive. For both the ilium and femur lengths, I arrived at almost identical scaling errors to Scott, and the legs should - according to the data in the paper - be c. 25-27% larger in the reconstruction. Something - the original measurements of the specimen or the reconstruction - just doesn't add up, and I suspect the latter, as I figure someone would have owned up to and corrected simple numerical errors in the paper by now. My working is below.

[amanda]

All right. Lemme try this again, then. The most commonly accepted reconstruction of Spinosaurus is something I have questioned before, given the lack of any real fossil evidence to back it up. (Before this release. ) I was told it was logical, as many other spinosaurids had those proportions. Essentially the missing pieces were taken and scaled up from other related species.

Now this animal, which does have fossil evidence, is partly being critiqued for being made of several different animals (of the same species) at different sizes and age groups, all essentially scaled up, and this is causing the scaling error. It is being called a Chimera, and most uncharitably, a "hodgepodge".

Now, which is the worse Chimera then? One constructed with educated guesses, based on fairly logical conclusions but still based in imagination, or one constructed out of actual fossil material? Skepticism is a good and healthy thing, but I have seen many on-line articles delve into outright ire and scorn It's...unseemly to me. Which is why I am willing to wait and see on more evidence. My most favorite sentence for now is"now we all know scaling from photographs is inherently precise.....so that's how I did it....".

Personally, to me it seems as if the feathered, flying dinosaurs were on the short track to give the pterosaurs some serious competition. Dinosaurs adapted to fill nerely every terrestrial niche there was, thoroughly dominating mammals there. I see no reason to think they would have stopped there. Why not adaptations to aquatic life? Why not eventually giving marine reptiles competition too. If not for sudden extinction, where would they have gone? I would have thought just pondering these possibilities would be exciting, that the debate would be visceral and fascinating. But no, no it's not and I do not get why?

[stargatedalek]

even with these rescaled legs they are still small, and still highly evident of a primarily aquatic life

[Balaur]

even with these rescaled legs they are still small, and still highly evident of a primarily aquatic life

Totally agree.

Also, if it did inhabit the mangroves, and it did go out into shallow oceans, then why did it go extinct? From my understanding, the river system was flooded, but Spinosauris could go out into the ocean. Is there something I'm missing?

[stargatedalek]

perhaps the sandy beaches became replaced by cliffs

[Patrx]

New from Mark Witton's blog: The Spinosaurus hindlimb controversy: a detailed response from the authors

[Megalosaurus]

Very interesting response. Lets wait for Mr. Hartman conclusions.

---

The first time I see this image I was shocked: A SIX legged Spinosaur!!! Then I read and watch carefully the image.


So I made this reconstruction using the above drawing as reference. 100% accurate as you can see.

[tyrantqueen]

Lol, yeah, I thought something similar too. Actually it reminded me of a Hexadragon



More like a Hexaspino

[reinier zwanink]

We can throw all our spinos out the window now
Looks like there is still a lot of speculation left for this one

[amargasaurus cazaui]

Spinosaurus itself has always been very speculative but people chose to ignore that and accept the dinosaur as given, despite alot of problems with the reconstruction

[darylj]

I remember starting a thread regarding spino years ago
. What I still struggle with is why a creature of this size had a sail. Even more so now it's considered aquatic. How does that monstrous back growth help in anyway. And why oh why was it not present in other species like baryonyx?

All I can picture is a creature that lived floating on the surface with only it's sail out of the water, somehow using its sail to keep warm and thus not having to leave the water. With say, baryonyx not quite as aquatic?
But then, how does a creature with a huge sail hunt?  I mean... You'd see it coming a mile off!
So I assume it hunted downward, as in things below it....
Maybe floating, using its sail to block the sun causing shadows, which maybe somehow helped catch a certain fish??
I just can't get my head around this creature... Something doesn't add up.....

[Balaur]

It seems like it was used for display. There is no evidence that it was ectothermic or endothermic, and in water it seems unlikely it was used for shadowing. It's like deer antlers. Why grow such cumbersome display structures? Naturw works in mysterious ways.

[darylj]

But even deer antlers get used for fighting, and don't really hinder the animals movement?

[amargasaurus cazaui]

Is it possible the sail was used for swimming in deeper water, as a steering aid or perhaps to achieve an up down perspective in water that was over its head?I find it no small coincidence that fish have a fin on top of their body as well...or consider swordfish and large sharks

[stargatedalek]

-deer antlers have been known to hinder movement, deer have even died from getting trapped by them

-perhaps the ridge had a buoyancy function?

[tyrantqueen]

Wasn't there a report of two stags rutting with their antlers, and getting locked together? They couldn't get free and eventually they starved to death.

[Gwangi]

Wasn't there a report of two stags rutting with their antlers, and getting locked together? They couldn't get free and eventually they starved to death.

That actually happens fairly often.

[SBell]

I remember starting a thread regarding spino years ago
. What I still struggle with is why a creature of this size had a sail. Even more so now it's considered aquatic. How does that monstrous back growth help in anyway. And why oh why was it not present in other species like baryonyx?

All I can picture is a creature that lived floating on the surface with only it's sail out of the water, somehow using its sail to keep warm and thus not having to leave the water. With say, baryonyx not quite as aquatic?
But then, how does a creature with a huge sail hunt?  I mean... You'd see it coming a mile off!
So I assume it hunted downward, as in things below it....
Maybe floating, using its sail to block the sun causing shadows, which maybe somehow helped catch a certain fish??
I just can't get my head around this creature... Something doesn't add up.....

There are modern birds that hunt by creating shadows--fish are drawn to the dark spaces. And then they get eaten.

And seeing something a mile off doesn't matter if the prey isn't above water--like most fish. So it may have been for heat absorption and keeping the animal's metabolism up while submerged.

As for adding up--it doesn't matter. The creature, in some form, existed. It's our challenge to figure it out.

[Gwangi]

There are modern birds that hunt by creating shadows--fish are drawn to the dark spaces. And then they get eaten.

The technique used by the black heron is just fantastic.