Jump to content

Sigilmassasaurus is Spinosaurus?


Haravex

Recommended Posts

So sadly its paywalled as usual I hope to read it soon but the general theme of the abstract seems to suggest various taxonomic of spinosaurus family are no longer valid. Again until I read the paper I wont say anything more than personally I'm highly skeptical.

 

https://www.sciencedirect.com/science/article/pii/S0195667120302068

  • I found this Informative 5
Link to comment
Share on other sites

Very cool now I need to get a hold of the paper and see what they have to say.  Ibrahims recent paper also makes comments similar to those in the abstract 

Link to comment
Share on other sites

what are your thoughts Troodon personally I don't see how they can be the same species, nut again dont have the paper to read yet.

Link to comment
Share on other sites

First need to read the paper, hey they are the experts not us.  Now we need to hear from S. Evers et al if they have a rebuttal since they described Sigilmassasaurus. 

Link to comment
Share on other sites

This is what you have when there are not a lot of articulated skeletons around.   

Link to comment
Share on other sites

BTW we have a similar debate with Carcharodontosaurus and Sauroniops.  Ibrahims et al. 2020 paper clearly argues that the evidence presented to describe Sauroniops is not valid.  Its great that we are seeing these publications may help to bring some clarity to the KK..

  • I found this Informative 1
Link to comment
Share on other sites

I dunno...

 

We know there are clear morphotypes for different spinosaurid bones. Cervical vertebrae, quadrates and frontals so far. And they are pretty distinct. And what I've seen there are dorsal vertebrae of that don't seem to match the same morphology. So there might be two morphotypes for dorsal vertebrae as well. I see differences in caudal vertebrae too.

 

For the rostrum I'd agree though. I can see the differences in that being the result of individual variation.

 

 

But the more I see of Kem Kem spinosaurs, the less I think it's the same taxon as the holotype from Egypt. Some scientists have suggested the Kem Kem spinosaurids should be a separate species or even genus based on the geography alone. I've begun to notice that the neural spines from Kem Kem are different to the Egypt holotype. Nearly all well preserved dorsal vertebrae from Kem Kem I've seen have the base of the neural spine further back than those of Stromer's holotype. This creates much more elongate prezygapopheses. In Stromer's holotype the neural spines are nicely centered.

And there are the weird angled dorsal vertebrae that @Troodon has posted before on this forum that simply do not fit at all in Ibrahim's reconstruction.
So if we're looking at a single species in both Egypt and Morocco then either there is some strong sexual dimorphism or sails varied wildly on an individual basis.

 

But imo, either we're looking at at least 2 distinct taxons in Kem Kem. Or we're looking at a single taxon that is distinct from Spinosaurus aegyptiacus.


Anyway it's nice more research is being done on this. Here are the enlarged images from the site. Lots of good reference pictures. Click to enlarge.

1-s2.0-S0195667120302068-gr1.jpg1-s2.0-S0195667120302068-gr2.jpg1-s2.0-S0195667120302068-gr3.jpg1-s2.0-S0195667120302068-gr4.jpg1-s2.0-S0195667120302068-gr5.jpg1-s2.0-S0195667120302068-gr6.jpg1-s2.0-S0195667120302068-gr7.jpg1-s2.0-S0195667120302068-gr8.jpg1-s2.0-S0195667120302068-gr9.jpg1-s2.0-S0195667120302068-gr10.jpg1-s2.0-S0195667120302068-gr11.jpg1-s2.0-S0195667120302068-gr12.jpg1-s2.0-S0195667120302068-gr13.jpg1-s2.0-S0195667120302068-gr14.jpg1-s2.0-S0195667120302068-gr15.jpg1-s2.0-S0195667120302068-gr16.jpg1-s2.0-S0195667120302068-gr17.jpg1-s2.0-S0195667120302068-gr18.jpg

  • I found this Informative 6

Olof Moleman AKA Lord Trilobite

Link to comment
Share on other sites

Always great to see no papers on KemKem and especially Spinosaurids from KemKem. Hopefully one day we have enough evidence for a final answer where everyone can agree on. 

Still hoping for a Spino "Sue". 

 

 

Since the holotype was mentioned and for some very quick refference so we have everything in one topic :) 

 

Here are the original drawings from the lost Holotype of Spinosaurus aegyptiacus, described and drawn by Stromer in 1915.

 

Spinosaurus_holotype.thumb.jpg.13efbd7c413eb199d45ea3e5801048b6.jpg

 

Spinosaurus_vertebrae.thumb.jpg.413afbdbe19a9781154d3c8757e6127f.jpg

 

 

I really like that they use the drawing from Stromer in this paper for comparison and reference. 

1-s2.0-S0195667120302068-gr9.jpg

 

 

And here the only two acutal photographs of the holotpye. As far as I'm aware there are no other acutal pictures.

 

spino-jaw_orig.jpg.f0b6b179d8a9436243f061ce4ec42529.jpg

 

spinosaurus-discovery-slide-SU3A-jumbo.jpg.3799137e4c90c5961aa4441ed0c82e72.jpg

  • I found this Informative 6
Link to comment
Share on other sites

 I was quite impressed with the paper and the arguments Smyth et al. put forward to support a single Spinosaurid being Spinosaurus aegyptiacus in the Kem Kem Group.  The validity of Spinosaurus maroccanus and Sigilmassasaurus brevicollis were seriously addressed in a very compelling manner.  They left no stone unturned and argued every issue ever presented which suggested multiple Spinosaurids in that region.  It included discussing every autapomorphy in Evers et al. paper that made Sigilmassasaurus distinctive, Hendrickx 2016 paper on unique quadrates and Richters 2013 paper on multiple tooth morphologies. 

 

It will be very interesting to see how Paleo community, blogs etc react to this publication especially the authors of all the  papers that were flagged.   Unfortunately we do not have much in articulated specimens to go by and have to use what is available to debate this issue.   Professional don't always get it right but I believe they did in this case but I'm sure the debate its far from over with new discoveries.

 

On a separate note the paper often pointed out that material presented in the paper was "commercially" acquired..thank goodness for diggers 

  • I found this Informative 6
Link to comment
Share on other sites

the legenda to plates one & two from Stromer:

styromer1000 (2).jpg

 

(arrow mine)

 

 

 

 

 

 

 

 

 

 

 

 

  • I found this Informative 1

 

 

 

Link to comment
Share on other sites

Christophe Hendrickx Twitter 

Paper  "No evidence is found to definitively support the presence of any spinosaur in the deposit besides Spinosaurus aegyptiacus. " 

Christophe:

"No evidence is found to definitively support the presence of a single spinosaur, Spinosaurus aegyptiacus, in the deposits"

"Previous confusion over the rejection of Sigilmassasaurus brevicollis has resulted in a system in which any variation between spinosaurid material is automatically assumed to be sexual dimorphism, intraspecific or ontogenetic variations"

 

And then  "A sarcastic remark"

Anyone have the new paper "Baryonyx, Ichthyovenator, Irritator, Suchomimus, and Vallibonavenatrix are Spinosaurus: a reappraisal of spinosaurids worldwide" by Smyth et al. (2025), please?

 

Obviously not very supportive of the reassessment 

 

Henry Sharpe posted

EYtyxN-XgAA1oEK.thumb.jpeg.cf8c4481df98076de432249dbccab9ba.jpeg

 

  • I found this Informative 4
Link to comment
Share on other sites

Ha ha Christophe ontogeny argument sounds a bit like those used against Nano.   Will be interesting to see how the rest of the paleo community reacts to this paper.   

  • I found this Informative 1
Link to comment
Share on other sites

  • 2 weeks later...

Hi All,

 

So I have been asked if Sauroniops is still even a valid genus? If so, what are the differences in physiology between it and Carcharodontosuarus? Can anyone help? Thank you

5d738606eab6e_2018-11-1322_54_57-Greenshot-newlogo.png

Link to comment
Share on other sites

30 minutes ago, Jaimin013 said:

Hi All,

 

So I have been asked if Sauroniops is still even a valid genus? If so, what are the differences in physiology between it and Carcharodontosuarus? Can anyone help? Thank you

Sauroniops is only known from a single forehead bone, nothing else. If it's even valid nothing can be said about differences in physiology.

  • I found this Informative 1

Olof Moleman AKA Lord Trilobite

Link to comment
Share on other sites

Agree,  with all of this new discoveries will be needed to continue to validate these species since so little is known.  The opinions in the paper are those of its authors and may not be shared by others like C. Hendrickx.  Unfortunately the KK is very slow on giving up its secrets.  

  • I found this Informative 2
Link to comment
Share on other sites

4 hours ago, LordTrilobite said:

Sauroniops is only known from a single forehead bone, nothing else. If it's even valid nothing can be said about differences in physiology.

 

3 hours ago, Troodon said:

Agree,  with all of this new discoveries will be needed to continue to validate these species since so little is known.  The opinions in the paper are those of its authors and may not be shared by others like C. Hendrickx.  Unfortunately the KK is very slow on giving up its secrets.  

Thanks alot both. I thought that might be the case but wanted to confirm first.

5d738606eab6e_2018-11-1322_54_57-Greenshot-newlogo.png

Link to comment
Share on other sites

  • 3 weeks later...
On 29/05/2020 at 11:33 AM, TyBoy said:

Ha ha Christophe ontogeny argument sounds a bit like those used against Nano.   Will be interesting to see how the rest of the paleo community reacts to this paper.   

Actually, I'm not using the ontogeny argument at all. I reviewed that paper and just said that the number of anatomical differences seen in the two quadrate morphotypes of the Kem Kem spinosaurines, which cannot be explained by ontogeny (as accepted by Smyth et al., 2020) and most likely not by sexual dimorphism (we are talking about two quite different morphologies of the mandibular articulation of the quadrate, with different functionality), favours intraspecific more than intraspecific variations. Indeed, the differences seen in the quadrates of Baryonyx and Suchomimus is as important, if not less important, than those displayed by the two quadrate morphotypes from the Kem Kem beds. Note that I consider Nanotyrannus and Raptorex as juvenile Tyrannosaurus and Tarbosaurus, respectively.

 

Anyway, I was being sarcastic on Twitter only because the sentence "No evidence is found to definitively support the presence of any spinosaur in the deposit besides Spinosaurus aegyptiacus. " can be used exactly the same way to discredit the presence of a single spinosaurid taxon ("No evidence is found to definitively support the presence of a single spinosaur, Spinosaurus aegyptiacus, in the deposits").

 

Cheers!

 

C.

 

 

  • I found this Informative 2
Link to comment
Share on other sites

59 minutes ago, Nekarius said:

 favours intraspecific more than intraspecific variations.

I assume you meant to say interspecific and intraspecific right?

 

 

Anyway, I'm inclined to agree. The differences seem pretty significant, not only in the quadrates but also in the frontal bones with the one morph having high set eyes and the other rather low. Other bones have been posted on this forum as well that do not match the Ibrahim Spinosaurus aegpytiacus reconstruction. Such as dorsal vertebrae with strongly retroverted thin neural spines. And I have a (likely) dorsal centrum from Kem Kem in my collection that looks like Spinosaurid. But it has a strong keel and so doesn't match Spinosaurus aegyptiacus.

 

I would be rather surprised if it does turn out that there really is only one taxon of Spinosaurid in the Kem Kem group.

Olof Moleman AKA Lord Trilobite

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...