Spinosaurus aegyptiacus/ Possible errors and reconstructions

[Dinoguy2]

No, incorrectly stated. There have been many finds of spinosaurid material. Most classify as baronchyine however. Actual findings of spinosaur material are limited to a possible seperate species from Morocco, and the finding on two occasions of teeth only that identifed as Spinosaurus. In addition to this you also have the irritator fossil, which seems to possess the same unserrated teeth as Spinosaurs do. Remember, suchomimus and baronyx are not Spinosaurs, they are spinosaurids. They also have serrated teeth, and Spinosaurs do not, which makes them similar, and cousins, but technically not Spinosaurs.

I'm not sure where you are getting you information, but you should become familiar with the theropod database, which lists every known theropod specimen.

http://home.comcast.net/~eoraptor/Megalosauroidea.htm#Spinosaurusaegyptiacus

As you can see, dozens of new Spinosaurus specimens have been found. S. moroccanus is no longer considered to be a distinct species by most researchers. All Spinosaurus, including Spinosaurus, has serrated teeth. See the paper describing dalSasso skull specimen for more information.

Note that even more complete specimens are known. However, morocco etc are plagued by commercial fossil dealers legally getting to all the good stuff long before scientists and selling them at auction. A nearly complete Spinosaurus skeleton was recently put on auction but not sold. It is still in the hands of a private company where no scientist can study and report it.

[amargasaurus cazaui]

The skull had a narrow snout filled with STRAIGHT conical teeth that LACKED serrations. There were six or seven teeth on each side of the very front of the upper jaw, in the premaxillae, and another twelve in both maxillae behind them. The second and third teeth on each side were noticeably larger than the rest of the teeth in the premaxilla, creating a space between them and the large teeth in the anterior maxilla; large teeth in the lower jaw faced this space. The very tip of the snout holding those few large anterior teeth was expanded, and a small crest was present in front of the eyes.[5] Using the dimensions of three specimens known as MSNM V4047, UCPC-2, and BSP 1912 VIII 19, and assuming that the postorbital part of the skull of MSNM V4047 had a shape similar to the postorbital part of the skull of Irritator, Dal Sasso et al. (2005) estimated that the skull of Spinosaurus was 1.75 meters (5.7 ft) long.[5] The Dal Sasso et al. skull length estimate was questioned because skull shapes can vary across spinosaurid species

Spinosaurus gives its name to the Spinosauridae family of dinosaurs, which includes two subfamilies: Baryonychinae and Spinosaurinae. The Baryonychinae include Baryonyx from southern England and Suchomimus from Niger in central Africa. The Spinosaurinae include Spinosaurus, Irritator from Brazil, and Angaturama (which is probably synonymous with Irritator) from Brazil.[5] The Spinosaurinae share UNSERRATED straight teeth that are widely spaced (e.g., 12 on one side of the maxilla), as opposed to the Baryonychinae which have SERRATED curved teeth that are numerous (e.g., 30 on one side of the maxilla).[5][17]



This material is the typical scientific basis for Spinosaurids, and Baryonychinae. Spinosaurs did NOT possess serrations on their teeth, and in fact this was one of the most remarkable criteria of the dinosaur when Stromer published his findings as he stated. If you read any book written about Stromer and his work, including but not limited to " Lost Dinosaurs of Egypt" that will demonstrate clearly that his find did not possess the serrated teeth that generally define carnivorous dinosaurs. It does not matter where you read the material, and in fact even Gwangi has stated the same, of the teeth being non-serrated in this thread if you review his postings.
  As to the many findings since, also incorrect. There are two known set of teeth findings that lacked serrations that can at this point be identified as Spinosaurus, and the Morrocan material which I did clearly mention by the way as being considered an invalid second species and therefore likely the same animal as Stromer's dinosaur.
  The Del Sasso paper has already been debunked and is considered flawed in several ways, mainly in his estimates and size and shape due to variations in size and shape of Spinosaur skulls
As to the major almost complete specimen offered for sale that exists in private hands. The simple facts about the material are very telling. Offered for sale and EVERY major museum that viewed it PASSED on it . That alone tells you alot about its validity. I cringe when people use unstudied material to try and reinforce points for this reason. You do not know if it is composited, original, its location of origin, its amount of original or restored material, and finally if the skeleton is even reconstructed properly. Does it posses serrated teeth or smooth? Is their a skull crest? The crucial things which suggest wether it is a true spinosaur or a cousin are many and without study or further view I am unsure why someone would try and validate the piece.
The simple fact is at this point it may or may not be, and having not seen nor studied it , it is irresponsible to try and use it as scientific proof of anything at this point.
 

[Horridus]

The simple facts about the material are very telling. Offered for sale and EVERY major museum that viewed it PASSED on it.

Or couldn't afford it.

[amargasaurus cazaui]

The simple facts about the material are very telling. Offered for sale and EVERY major museum that viewed it PASSED on it.

Or couldn't afford it.

Seemingly if you were considering what has been by some labeled " the holy grail of dinosaur fossils" just the casting rights, potential scientific value and so forth from such a piece would prove it rather profitable. Case in point is Sue the tyrannosaur. It has proven a cash windfall for the Chicago Field Museum. I doubt the financial consideration would be a detriment if the specimen were all it was alleged to be. That suggests to me that the specimen itself is lacking, is not that complete or has other issues. Possible that the cost might be a factor but I somewhat doubt it. Just far too many museums that have the ability to step forward and grab major fossils if desired enough.

[Dinoguy2]

The skull had a narrow snout filled with STRAIGHT conical teeth that LACKED serrations. There were six or seven teeth on each side of the very front of the upper jaw, in the premaxillae, and another twelve in both maxillae behind them. The second and third teeth on each side were noticeably larger than the rest of the teeth in the premaxilla, creating a space between them and the large teeth in the anterior maxilla; large teeth in the lower jaw faced this space. The very tip of the snout holding those few large anterior teeth was expanded, and a small crest was present in front of the eyes.[5] Using the dimensions of three specimens known as MSNM V4047, UCPC-2, and BSP 1912 VIII 19, and assuming that the postorbital part of the skull of MSNM V4047 had a shape similar to the postorbital part of the skull of Irritator, Dal Sasso et al. (2005) estimated that the skull of Spinosaurus was 1.75 meters (5.7 ft) long.[5] The Dal Sasso et al. skull length estimate was questioned because skull shapes can vary across spinosaurid species

Spinosaurus gives its name to the Spinosauridae family of dinosaurs, which includes two subfamilies: Baryonychinae and Spinosaurinae. The Baryonychinae include Baryonyx from southern England and Suchomimus from Niger in central Africa. The Spinosaurinae include Spinosaurus, Irritator from Brazil, and Angaturama (which is probably synonymous with Irritator) from Brazil.[5] The Spinosaurinae share UNSERRATED straight teeth that are widely spaced (e.g., 12 on one side of the maxilla), as opposed to the Baryonychinae which have SERRATED curved teeth that are numerous (e.g., 30 on one side of the maxilla).[5][17]



This material is the typical scientific basis for Spinosaurids, and Baryonychinae. Spinosaurs did NOT possess serrations on their teeth, and in fact this was one of the most remarkable criteria of the dinosaur when Stromer published his findings as he stated. If you read any book written about Stromer and his work, including but not limited to " Lost Dinosaurs of Egypt" that will demonstrate clearly that his find did not possess the serrated teeth that generally define carnivorous dinosaurs. It does not matter where you read the material, and in fact even Gwangi has stated the same, of the teeth being non-serrated in this thread if you review his postings.
  As to the many findings since, also incorrect. There are two known set of teeth findings that lacked serrations that can at this point be identified as Spinosaurus, and the Morrocan material which I did clearly mention by the way as being considered an invalid second species and therefore likely the same animal as Stromer's dinosaur.
  The Del Sasso paper has already been debunked and is considered flawed in several ways, mainly in his estimates and size and shape due to variations in size and shape of Spinosaur skulls

Debunked by whom, in what paper?

It sounds like you have already made up your mind about this and any contrary evidence is invalid. Thats the no true Scotsman fallacy. I certainly Can't argue against that.

[amargasaurus cazaui]

The skull had a narrow snout filled with STRAIGHT conical teeth that LACKED serrations. There were six or seven teeth on each side of the very front of the upper jaw, in the premaxillae, and another twelve in both maxillae behind them. The second and third teeth on each side were noticeably larger than the rest of the teeth in the premaxilla, creating a space between them and the large teeth in the anterior maxilla; large teeth in the lower jaw faced this space. The very tip of the snout holding those few large anterior teeth was expanded, and a small crest was present in front of the eyes.[5] Using the dimensions of three specimens known as MSNM V4047, UCPC-2, and BSP 1912 VIII 19, and assuming that the postorbital part of the skull of MSNM V4047 had a shape similar to the postorbital part of the skull of Irritator, Dal Sasso et al. (2005) estimated that the skull of Spinosaurus was 1.75 meters (5.7 ft) long.[5] The Dal Sasso et al. skull length estimate was questioned because skull shapes can vary across spinosaurid species

Spinosaurus gives its name to the Spinosauridae family of dinosaurs, which includes two subfamilies: Baryonychinae and Spinosaurinae. The Baryonychinae include Baryonyx from southern England and Suchomimus from Niger in central Africa. The Spinosaurinae include Spinosaurus, Irritator from Brazil, and Angaturama (which is probably synonymous with Irritator) from Brazil.[5] The Spinosaurinae share UNSERRATED straight teeth that are widely spaced (e.g., 12 on one side of the maxilla), as opposed to the Baryonychinae which have SERRATED curved teeth that are numerous (e.g., 30 on one side of the maxilla).[5][17]



This material is the typical scientific basis for Spinosaurids, and Baryonychinae. Spinosaurs did NOT possess serrations on their teeth, and in fact this was one of the most remarkable criteria of the dinosaur when Stromer published his findings as he stated. If you read any book written about Stromer and his work, including but not limited to " Lost Dinosaurs of Egypt" that will demonstrate clearly that his find did not possess the serrated teeth that generally define carnivorous dinosaurs. It does not matter where you read the material, and in fact even Gwangi has stated the same, of the teeth being non-serrated in this thread if you review his postings.
  As to the many findings since, also incorrect. There are two known set of teeth findings that lacked serrations that can at this point be identified as Spinosaurus, and the Morrocan material which I did clearly mention by the way as being considered an invalid second species and therefore likely the same animal as Stromer's dinosaur.
  The Del Sasso paper has already been debunked and is considered flawed in several ways, mainly in his estimates and size and shape due to variations in size and shape of Spinosaur skulls

Debunked by whom, in what paper?

It sounds like you have already made up your mind about this and any contrary evidence is invalid. Thats the no true Scotsman fallacy. I certainly Can't argue against that.

I am sorry you feel that way. I stated at the opening of the thread quite clearly and made certain to differentiate that Spinosaurus as Stromer described the fossil had non-serrated teeth, and in fact this was part of the reason I QUESTIONED the reconstruction. The other spinosaurids do seem almost all to have serrated teeth. Add to this as I clearly stated at the start of the thread that within the material he was working with he also named at least six crocdilyforms, which it would seem plausible would have non-serrated teeth.This is all well documented scientific literature and nothing I have "made my mind up about" . It is established material done around a hundred years ago, and examined and re-examined. He described an animal with smooth non serrated teeth.
Since the discovery of other spinosaurids, it has become common practice to assign them within either the spinosaur branch or the baryonychinae, and one of the prime determining factors IS their smooth or serrated teeth. Those are not things I chose or decided, it is just how it is.
The two paragraphs I pasted are from different sources that state the same facts. In addition there are other members of the forum who despite agreeing with Stromers interprations of the animal do accept that the dinosaur had non serrated teeth.
  As to the Dal Sasso paper, his methods of measuring and determining the size of Spinosaur skulls were openly questioned as I pasted into the forum already. It was felt that you cannot use other Spinosaur species to attempt to specify size of shape of the Stromer animal as the species vary in shape, fossilzation relics and so forth. Again, this is not something I said or decided, it was done by scientists. Thanks

[Seijun]

So to sum up, do they or do they not have serrated teeth? (spinosaurs). I am speaking in reference to existing spinosaur teeth.

[amargasaurus cazaui]

So to sum up, do they or do they not have serrated teeth? (spinosaurs). I am speaking in reference to existing spinosaur teeth.

The bottom line seems to be this. Spinosaurs do not have serrations on their teeth, and baryonychine do. Both are families within the spinosaurids, thus seeming to confuse everyone. Stromers animal clearly did not and he wrote his description stating precisely that. Anything classified as a true Spinosaurs does NOT have serrated teeth according to the books and material...ie Irritator  Anything with serrated teeth in this grouping is generally named baryonychine. (suchomimus, baronyx, etc.)

[Horridus]

Seemingly if you were considering what has been by some labeled " the holy grail of dinosaur fossils" just the casting rights, potential scientific value and so forth from such a piece would prove it rather profitable. Case in point is Sue the tyrannosaur. It has proven a cash windfall for the Chicago Field Museum. I doubt the financial consideration would be a detriment if the specimen were all it was alleged to be.

The Field Museum did buy Sue, but only because a number of large corporations (and some individual donors) donated money to them as a philanthropic gesture so that they could do so. Museums just don't have those sorts of sums to spare.

By the way, you need to be saying 'spinosaurines' instead of spinosaurs. A 'spinosaur' could be a Spinosaurus, spinosaurine, spinosaurid or even spinosauroid.

[Gryphoceratops]

So to sum up, do they or do they not have serrated teeth? (spinosaurs). I am speaking in reference to existing spinosaur teeth.

The bottom line seems to be this. Spinosaurs do not have serrations on their teeth, and baryonychine do. Both are families within the spinosaurids, thus seeming to confuse everyone. Stromers animal clearly did not and he wrote his description stating precisely that. Anything classified as a true Spinosaurs does NOT have serrated teeth according to the books and material...ie Irritator  Anything with serrated teeth in this grouping is generally named baryonychine. (suchomimus, baronyx, etc.)

Don't say that.  I told you I was going to look for a better source to back me up didn't I?  This is a scientific paper about spinosaurus teeth from 2010 and was given to me by a credible person in the paleo world. 

http://www.gmnh.pref.gunma.jp/research/no_14/bulletin14_2.pdf

As it turns out animals in the genus Spinosaurus don't have true serrations.  But they DO have what are called carinas which are a sort of ridge going up the length of the tooth.  Think of it as a really safe butter knife as opposed to a steak knife.  Regardless they are different from crocodile teeth which wouldn't have any ridge or serrations at all which is what this whole debate was about in the first place.   

[amargasaurus cazaui]

That is an awesome paper gryph thanks for sharing. He made some rather interesting comments that fit well with the questions I have posed I feel. It is a rather well stated work and shows exactly what I was trying to question from the start about Stromer's work. Stromer described his dinosaur as having no serrations on the teeth he found, and Stromer was also naming crocodyliforms from the material he recovered the dinosaur from, precisely the scenario the author of the paper mentions.
(I also wondered if you attach much importance to this sentence about the tooth differing significantly from others previously reported  as the author once more states similar again further.)



                    The micro-structures described herein significantly differ from the ones previously
                    reported in the literature. Some possilble spinosaurids teeth previously reported is more  likely   to be from a crocodile



He then goes on later to state once more........."The tooth specimen reported in the present
study is significantly different in our knowledge from all the
teeth specimens figured in the studies listed earlier"





  The author of the paper clearly states a similar conclusion, that it is quite possible many of the known spinosaur teeth are actually not from the dinosaur , and gave specific examples.
  He also did seem to suggest that the Baryonychines have much more pronounced striations than the Spinosaurines, which could be one reason most of the published literature today states the Spinosaurines had no serrations to their teeth whereas the others did.
  So in proper verbage, would you feel it correct to state ALL spinosaurids,lacked serrations to their teeth, and rather had a structure called a carinae which is a fine striation which is more pronounced in the  Baryonychines , but makes these animals teeth similar to crocodilians, mosasaurs, and even some whales?

Long conical, striated teeth independently
evloved in spinosaurid theropods, crocodiles, mosasaurs,
plesiosaurs, ichthyosaurs, and even in whales

[amargasaurus cazaui]

So to sum up, do they or do they not have serrated teeth? (spinosaurs). I am speaking in reference to existing spinosaur teeth.

As it turns out animals in the genus Spinosaurus don't have true serrations.  But they DO have what are called carinas which are a sort of ridge going up the length of the tooth.  Think of it as a really safe butter knife as opposed to a steak knife.  Regardless they are different from crocodile teeth which wouldn't have any ridge or serrations at all which is what this whole debate was about in the first place.

Wait, the author does state many crocodilians had quite similar teeth with similar striations. He states this in several places in the paper.

[Gryphoceratops]

The person I spoke to said depending on how much of the tooth is found, it is also possible to distinguish it as from a theropod dinosaur and not a crocodile or something else by the shape of the root of the tooth.  None of this was mentioned in the paper I don't think (if it was I missed it).  The point is they do differentiate from each other despite their similarities. 

[amargasaurus cazaui]

The person I spoke to said depending on how much of the tooth is found, it is also possible to distinguish it as from a theropod dinosaur and not a crocodile or something else by the shape of the root of the tooth.  None of this was mentioned in the paper I don't think (if it was I missed it).  The point is they do differentiate from each other despite their similarities.

Right, I can see where the root might be more diagnostic than the tooth. The author also stated that identifying invidual teeth without the jaw is not accurate, but at least if you had the root or point of attachment that might help to see if it were socketed or fused for instance. I also saw nothing about that point in the paper.

[amargasaurus cazaui]

The person I spoke to said depending on how much of the tooth is found, it is also possible to distinguish it as from a theropod dinosaur and not a crocodile or something else by the shape of the root of the tooth.  None of this was mentioned in the paper I don't think (if it was I missed it).  The point is they do differentiate from each other despite their similarities.

Right, I can see where the root might be more diagnostic than the tooth. The author also stated that identifying invidual teeth without the jaw is not accurate, but at least if you had the root or point of attachment that might help to see if it were socketed or fused for instance. I also saw nothing about that point in the paper.

I did want to thank you for sharing that with me and taking the necessary time Gryph, it is MOST helpful and gives alot of information and I do appreciate it, thanks so very much

[Gryphoceratops]

Your welcome.   

And no they didn't mention anything about roots in the paper it was purely just about the ridges and serrations.  The paleontologist I got it from mentioned that part himself since it wasn't included in there.