The Outlaw Spino Saurus


There’s been a lot of news now about Thursday’s (Sep. 11, 2014) publication on a new specimen attributed to Spinosaurus aegyptiacus. A lot of hype rose up months back about the release of  a photo of a mount of some unusual bones, and what that entailed. As with every fossil discovery, caution had to be carefully tended in regards this mount because we had no idea what it was based on. This mystery was spoiled, and it seems the culprit was wilier than we all thought.

It always pays to be cautious as a paleontologist; invested as we are in our own discoveries, we know that science is an ever-marching progress of information. Some (much!) of what we work with is very incomplete. This appears to be even more problematic when what we talk about is very, very interesting not only to other professionals but to the lay public. Spinosaurus! It’s the animal that “defeated” the king in that one movie! It had a crocodile head and a theropod body, with a giant sail on its back!

But as I wrote back in May of 2010, Spinosaurus aegyptiacus may not be as we know it. Many reconstructions suggested it was sailed only above its back, but there’s evidence to support the sail was shallower and gradual over the back. In their new paper, Ibrahim et al. (2014) provide some radical new interpretations of a specimen found in the Cenomanian of the Kem Kem of Morocco, over 3k miles from the original discovery site at the oasis of Baharija in central Egypt. On the way from its original description to today, the original material had been destroyed (but not after being well-photographed and mounted) and new material began to come to light across the northern African nations of the north Sahara regions in Tunisia, Algeria, and Morocco. These sites were unusual in that they indicated a paludal, brackish marsh water environment, much akin to the swamps of Louisiana in the United States, or the brackish lagoons of Venice.

Life in a swamp, especially if you’re a giant, requires some interesting adaptations. Maybe. The authors describe the body, preserved incompletely from some dorsals and much of a hind limb and some parts of the tail, of a fairly small individual — smaller than the original specimen from Egypt, certainly — that provides the first semi-articulated skeleton of Spinosaurus aegyptiacus. Ibrahim et al. then go on to perform a series of analyses, corroborating some hypotheses posed before them, and coming up with a few novel ideas of their own. For example, the internal anatomy of the snout MSNM V4047 (possibly the largest known Spinosaurus specimen (but maybe not necessarily Spinosaurus aegyptiacus) suggesting that the snout was very extensively innervated and thus likely surrounded in life by dense sensory tissues, the composition of the teeth allowing an isotope analysis proving a diet comprised primarily of nearshore marine fish, and some peculiar adaptations of the limbs that imply a semiaquatic lifestyle. These things are interesting, croc-like in some results, and not really all that controversial.

But the devil is in the details, and as some have been noting over the past few days, these details leave one scratching their head.

Dachshund?

There’s the issue with the body proportions and the tiny legs and hips. This is provided in both the mount and a digital skeletal reconstruction, of an animal so inept it couldn’t walk bipedally, almost certainly a quadruped and prone to swimming more than walking. And it doesn’t appear to match the given measurements and scaling provided by the authors themselves. When scaled to their actual measurements, the slinky long body disappears, the legs are able to stand upright, and without support from the massive forelimbs.

But let us consider some additional factors. First, the forelimbs, if they are anything like normal theropod forelimbs, are completely unsuited for weight-bearing. Rather than arranged vertically, the shoulder blades are aligned across the ribs in such a way that any quadrupedal stance would shove the shoulders deep into the neck and likely behead a Spinosaurus faster than Sean Bean in his next deat–film. Rather, they were suspended as in other theropods free from the ground, to dangle as they please.

Second, the authors even provide a furcula (recovered with the spinosaur Suchomimus tenerensis) for the shoulder, and this would have kept the shoulders from moving independently of one another, meaning it is unlikely the arms were permitted to walk in anything like a natural gait or a “typical” quadruped.

Third, the forelimbs while massive have not been described in sufficient detail and appear to possess characteristic typical of other spinosaurs. If they are anything like the forearms of Baryonyx walkeri, they’d lack almost any quadrupedal attributes, especially in the metacarpus, manus, and especially in the phalanges. The authors propose a semi-knuckle-walking locomotion style, but all extant knuckle-walkers have specific adaptations of the arm to permit this (and so it appears in extinct ones, even if you include chalicotheres which may not have been knuckle-walkers), including the presence of thickened, columnar first phalanges and strong curling joints for the other phalanges to bring them out-of-the-way, as well as thickened, solid wrists. Theropods, rather, have flexible wrists due to the semilunate carpal hinge and would likely have been unable to bear weight translating through the upper into the lower arm, much less straighten the limb passively enough to bear weight in such a fashion that a knuckle-walker would require. Yet that is exactly what the authors describe.

An Unlikely Reconstruction

Ibrahim et al. (2014) make some bones about the reconstruction they provide showing evidence for a very forward center of gravity, which would have necessitated either aquatic habitus, quadrupedalism, or both. However, this reconstruction, as noted by Scott Hartman in the link at the top of the previous section, is a composite. It is composed not merely of the implied association between the holotype and the new specimen, but additionally of material von Stromer originally called “Spinosaurus B” and what Dale Russell named as Spinosaurus maroccanus as well as Sigilmassassaurus brevicollis. Caught up in all this were the work of Sereno and others who attempted to qualify the relations of these specimens to one another and t other Baharija taxa, such as Carcharodontosaurus. Sereno et al. (1996), in their description of a new skull of Carcharodontosaurus, also described a vertebra very similar to the Moroccan Sigilmassasaurus as well as the Egyptian Spinosaurus B. They then synonymized the three (Sereno et al., 1998). Later on, McFeeters et al. (2013) addressed this issue and separated Sigilmassasaurus (and Spinsoaurus B) from Carcharodontosaurus. They weren’t the same, and Sereno et al. were incorrect in their assumption that association between the skull of the carcharodontosaur and the vertebrae meant they were the same animal. They also further argued the western (Moroccan) and eastern (Egyptian) specimens represented distinct forms, possibly distinct species; they weren’t identical, even if you assumed positional variation. Ibrahim et al. (2014) however completely ignore this and instead referred Sigilmassasaurus brevicollis and Spinosaurus B into Spinosaurus aegyptiacus. This is followed by referral of the skull MSNM V4047 to aegyptiacus. Despite some taxic distinction between west and east, Ibrahim et al. have supported a contiguous north African province. Michael Mortimer has a bit more to say on this here.

This clouds their skeletal reconstruction, as it provides material from the new specimen, the Moroccan specimens listed above, and the holotype. And the scaling seems to be off. Moving from the head into the neck, it is clear that the reconstruction of the vertebral spines makes an abrupt transition from tall and spindly, as in Acrocanthosaurus and Spinosaurus‘s holotype, into the thin nubbin-like processes of Sigilmassasaurus brevicollis, then immediately back into the tall and very slender spines of the anterior dorsum of Spinosaurus‘s holotype and the new specimen. The neck seems overly long. Its high S-shaped arch is composed of the unusually strong flexure in Sigilmassasaurus brevicollis and the elongate vertebrae of Spinosaurus aeygptiacus.

Ibrahim et al. (2014) reverse the trend recently to see the last, tallest vertebral spine as a caudal (Andrea Cau, Scott Hartman, and myself) and pull the arch of the sail over the hips, and plop it right back into von Stromer’s and Lydekker’s last-dorsal position with corresponding sharp drop-off in height over the hips and into the tail. Ibrahim et al. (2014) describe new caudal material, but as it turns out none of the material represents anterior caudals, and instead the authors place the ambiguous caudal of the holotype into the most anterior (read, first caudal) position possible. As I discussed here, this is unlikely. As it is, none of the caudal vertebrae seem to be anterior further anterior than about half of the tail’s length, assuming about 50 caudals.

Then, as pointed out by Scott Hartman, the hip and hindlimbs do not correspond well to the vertebrae given the measurements in the paper itself. This may be a problem with the measuring, the scaling of the reconstruction, or a little of both. There is now ambiguity to be resolved. Yet what is clear is this: The skeleton is a chimera, and is composed of material safely ensconced in other taxa: Sigilmassasaurus brevicollis from Morocco, “Sigilmassasaurus” from Egypt, disparate forelimb material collected in the Kem Kem, the holotype from Egypt, and the referred specimen from the Kem Kem. It seems unreasonable to assume a single taxon amongst these disparate (and distinct) materials, even without so handy a specimen as a Rosetta stone as, say, the holotype of Anzu wylei serves for Caenagnathidae. Thus, the skeletal reconstruction is simply not to be trusted, and the mount it is based on almost certainly a fantasy.

Perhaps I am being overly harsh on the authors, but given the high-profile and low detail presentation of their paper and it’s extensive (and openly accessible) supplemental data, we have more questions and less certainty with this new material (very little of which is separately described in the paper or supplement) than we had before. More radical is proposed than is resolved.

A quadrupedal spinosaur? I think not. Biomechanically, the forelimbs wouldn’t allow it, and the proportions done either. This doesn’t mean the animal wasn’t adapted for wading through muck and along the marshy shores of an ancient sea. Most likely it could swim, but I’d imagine so could most theropods so this is hardly surprising. Was it some predatory hippo? More croc-like than we imagine? Probably not.

(In an interesting aside, the authors reconstruct the upper and lower jaws of Spinosaurus as having only a two-tooth overbite, a reconstruction I may add I provided a while back.)

What of Spinosaurus?

It’s no secret we lost the holotype. This leaves us a gap in our knowledge of one of the most captivating, mysterious dinosaurs (that’s a theropod; a candle to the torch that is Amphicoelias). The urge to fill this gap and provide a safe, stable container for the large spinsoaurid material for north Africa is a commendable one. Ibrahim et al. (2014) chose to go ahead and make their new specimen, FSAC-KK 11888, the neotype (or “new name bearing specimen”) of Spinosaurus aegyptiacus. Ironically, from a specimen in Morocco. This defies two points the authors raise about the necessity of this action and the steps taken to carry it through. First, that there was every effort made to ensure consistency with the original record and locality, and to preserve the original intent of the first type’s designation; and second, that there is a timely, necessary need to create a stable record for the name.

Regardless of what happened to the specimen, von Stromer was very thorough, and provides while not a perfect record of collection, preparation and microscopic details a substantive physical and superficial description with measurements and excellent illustrations. Moreover, there’s a photograph of the original mount and reference to the description reveals what is reconstructed and what is authentic. This data is strong and possibly precludes the need for a new type so readily that one might pick a specimen of a likely distinct taxon as the new name-bearing type and to then dump into this what are additional possible distinct species. Ibrahim et al. (2014) further argue that this is predicated almost entirely on the intent of von Stromer to call attention (via nomenclature) to the spines as highly distinct. Yet, I would argue (and have) that the base element, the most diagnostic and distinct element, is the mandible; and if one were to split the specimen due to speculation, I’d tie the name-bearing type to the jaw. Ibrahim et al. (2014) focus on many postcranial attributes because there is so very little cranial material to go by, and that is the prime issue involved here. We might very well expect distinct, closely related species to vary only in small details of vertebrae, as Sigilmassasaurus and Spinosaurus B do; so, too, then in the jaw.

As such, I do not think the need for a neotype is warranted; though whether or not I disagree, the authors seem to satisfy the ICZN.

Dal Sasso, C., Maganuco, S., Buffetaut, E. & Mendez, M. A. 2005. New information on the skull of the enigmatic theropod Spinosaurus, with remarks on its sizes and affinities. Journal of Vertebrate Paleontology 25 (4): 888-896.
Ibrahim, N., Sereno, P. C., Dal Sasso, C., Maganuco, S., Fabbri, M., Martill, D. M., Zouhri, S., Myhrvold, N. & Iurino, D. A, 2014. Semiaquatic adaptations in a giant predatory dinosaur. Science (Science Express, early online, 10.1126/science.1258750)
McFeeters, B., Ryan, M. J., Hinic-Frlog, S. & Schröder-Adams, C. 2013. A reevaluation of Sigilmassasaurus brevicollis (Dinosauria) from the Cretaceous of Morocco. Canadian Journal of Earth Sciences 50  (6): 636-349.
Russell, D. A. 1996. Isolated dinosaur bones from the middle Cretaceous of the Tafilalt, Morocco. Bulletin du Muséum National d’Histoire Naturelle, Paris, Série 4 18: 349-402.
Sereno, P. C., Dutheil, D. B., Iarochene, M., Larsson, H. C. E., Lyon, G. H., Magwene, P. M., Sidor, C. A., Varricchio, D. J. & Wilson, J. A. 1996. Predatory dinosaurs from the Sahara and Late Cretaceous faunal differentiation. Science 272: 986-991.
Sereno, P. C., Beck, A. L., Dutheuil, D. B., Gado, B., Larsson, H. C. E., Lyon, G. H., Marcot, J. D., Rauhut, O. W. M., Sadleir, R. W., Sidor, C. A., Varricchio, D. J., Wilson, G. P. & Wilson, J. A. 1998. A long-snouted predatory dinosaur from Africa and the evolution of spinosaurids. Science 282: 1298-1302.
von Stromer, E. 1915. Ergebnisse der Forschungreisen Prof. E. Stromers in den Wüsten-Ägyptens. II. Wirbeltier-Reste der Baharîje-Stufe (unterstes Cenoman). 3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen. et nov. spec. [Results of the explorations of Prof. E. Stromer in the Egyptian desert. II. Vertebrate remains of the Bahariya Formation (lowest Cenomanian). 3. The original of the theropod Spinosaurus aegyptiacus nov. gen. et nov. spec.] Abhandlungen der Königlichen Bayerischen Akademie der Wissenschaften Mathematisch-physikalische Klasse Abhandlung 28 (4): 1–32.

Advertisements
This entry was posted in Biology, Biomechanics, Paleontology, Science Reporting, Taxonomy and tagged , , , , , . Bookmark the permalink.

41 Responses to The Outlaw Spino Saurus

  1. Dean says:

    Great overview of the ups and downs (literally) of Spinosaurus. For completely personal reasons I’m glad to have it back on two legs, and I look forward to the sorting out of this material.

  2. ijreid says:

    Wow :) This is an amazing description of what is contestable about the paper, where corrections should be made, and why the reconstructions are inaccurate. As far as I can tell, you, as well as Scott Hartman, Mark Witton, and others discussed above, should publish the responsive paper to Ibrahim et al., which would go into much greater detail about the issues mentioned above. There has been some talk on the web that all old reconstructions should be revamped, but as you, Scott Hartman, and Mark Witton discuss on your respective blogs, any changes might not even be needed. Great detailed post on this issue!

  3. Having had to seek advice from ICZN commisioners on an analogous case a couple of years ago (see Taylor 2012), I would say that if what you say is correct, Ibrahim et al.‘s neotype designation does not satisfy the ICZN. The current code makes it pretty clear that neotypes are not to be designated as a matter of course, but only when they are absolutely necessary to settle uncertainty about a name’s application. If Stromer’s descriptions of the holotype prior to its destruction are adequate for the identification of Spinosaurus aegyptiacus relative to other spinosaurids, then a neotype is unnecessary even if the holotype is not physically available.

  4. Indeed, it sounds like Ibrahim et al.‘s taxonomic treatment confirms that they had no need for a neotype: if there was any difficulty distinguishing Spinosaurus and Sigilmassaurus, then a neotype might be necessary, but if they’re the same thing, then there’s no question of identity.

    • Does this then allow us to ignore the act of raising a neotype?

      • Perhaps not ‘ignore’, per se, but it does mean that you’re not obligated to accept it.

        • Oliver Rauhut says:

          Well, the matter even gets more complicated if there is more than one taxon (and we have Spinosaurus marocannus and Sigilmassasaurus to choose from, and both have an existing holotype) and it is unclear what Ibrahim et al.’s neotype actually represents. If there is a distinction between Spinosaurus from Egypt and Spinosaurus/Sigilmassasaurus from Morocco, as you suggest, their new specimen might represent the latter, in which case it represents a species for which we have a valid holotype.

          • This is precisely my problem when broad lumping of disparate formations widely separated in space and with some acknowledged taxic differences amongst species are noted. Moderate but even low diversity between the Tafilalt, Kem Kem, and Baharija should lend caution to taxic lumping and lead authors to substantiate their taxa on firmer grounds. Can differences be found? Yes. Are they substantive? Don’t know. We now have only two sets of spinosaur vertebrae from the northern Sahara, and lots of isolated parts of others; claiming lack of diversity and substantial cause to lump them, including the lumping in on some rather generous terms of other species (that show themselves substantial differences — e.g., the tibia of Spinosaurus B and the new specimen), should be reason for caution.

            The best course should always be for the least taxonomic actions needed to achieve stability and parsimony with provided hypotheses. This taxonomic quandary leads to neither.

  5. “Was it some predatory hippo? … Probably not.”

    What about the relatively dense limb bones?

    • I’d be cautious about this without properly assessing the cortical density of OTHER bones. For example, ribs, and the vertebrae in Suchomimus, and the pelvis and scapula/humerus. Such values would be just as important to assess, when compared to the proportions argued for.

      As for what the bone density means, it is true that diving birds and mostly-submerged animals tend to have higher bone density than others, but this isn’t always true, and it’s the pervasiveness of density that matters rather than the presence in some bones. In crocodilians, the limbs are not particularly dense, and they use gastroliths for ballast, whereas in diving birds, bone density can be high (grebes, penguins) but also relatively low (plunge divers like pelicans and terns). Some cetaceans also reduce bone density as they develop other means of increasing relative denstiy (such as expelling air from the lungs), or in the case of seals by simply being extremely mobile as increased bone density makes it harder to move rapidly through the water column.

      In the evolution of whales at least as well as aquatic mustelids, the pre-aquatic forms show limb-bone density higher than “typical” terrestrial forms and before proportions start changing, so Indohyus had “aquatic-adapted” bones, but was still typically cursorial in its limb proportions. These lines of evidence suggest at the minimum that Spinosaurus spent a fair amount of its time hunting food in water. It doesn’t mean it waded around and swam all the time there, or, like the hippo, is known primarily as a swimmer; merely that it pursued prey in the water enough to evolve means of not fighting against its internal air for bouyancy.

      • But thing is, said birds are plunge divers, not specialised underwater pursuit predators. Most seabirds that forage underwater do indeed show higher bone density.

        Likewise, Spinosaurus’ bone density seems to have inferred a phenomenal weight, around the size of small-to-mid-size sauropods.

  6. Pingback: Spinosaurus: Der schwimmende Riesensaurier – Hier wohnen Drachen

  7. coelophysis says:

    n.g. laelaps says that it was hypothesis how they fit every dinosaur into the new spinosaur may be heat got to them but clearly its more crocodilian than the other spinosauridae with whale nose and crocodilian tail clearly more aquatic and mite be quadrupedal with small legs and do not have gasping hands like early spinosauridae and mite use the death role sail to swim better but it has croc tail does not need it since the early spinosauridae crocodilian came from them and they are quadrupedal so the advance spinosauridae should be quadrupedal

    • There are some questions on the form of modelling used to find a stable center of gravity and the argument made to support quadrupedalism in this specimen or in specimens of taxa like it. This will be handled eventually, as science moves on and the authors present their full data regarding their (admittedly very) short-form publication. Stay tuned.

  8. Nizar says:

    Hi,

    The proportions are correct (we will respond to Scott Hartmann’s message shortly) and are present in two associated skeletons (some of the images floating around the internet are misleading – note also that the femur in our digital skeleton is slightly bowed and difficult to measure on a computer screen). We know from different lines of evidence that “Sigilmassasaurus” remains belong to Spinosaurus. As far as comments on bone compactness are concerned, yes, we did look at other bone sections of Suchomimus. Note also that the name is not “von Stromer” (if anything it would be “von Reichenbach” – Ernst Stromer von Reichenbach).

    Best,

    Nizar

    • Hello! Thanks for replying, Nizar.

      1. If the proportions are stable between the two specimens (one Baharija, one Kem Kem) then I am fine with this basic assumption of two consistent specimens. However, it is not clear that the specimen from Baharija is itself consistent with itself. Full data on its collection and the relationship of the material is lost. I accept initially that the basic limb proportions between vertebrae and tibia are correct, however this does not mean the presented proportions in the SOM or the reconstruction are, as they clearly do not match. This is the core of that particular issue.

      2. I’m worried that very little of the new specimen’s different elements (with all cardinal views) was illustrated outside the figure in the paper, and almost not at all in the SOM. This has made it terribly inconvenient for outside workers to assess the properties of the specimen as reported. The display of the specimen in promotional material, including a full-view image, makes some interesting claims regarding the tail vertebral positions, anterior dorsals, placed as posterior with backwards-sloping spines, etc. None of these can be resolved despite the 40+ page SOM.

      3. I cannot rely on unpublished information or specimen association to consider any additional claim made on whether Sigilmassasaurus brevicollis is a synonym of any previously named taxon. What is clear from Stromer’s work is that vertebrae from the middle of the neck through to the sacrum remain taller than wide consistently (For “element B,” a middle to posterior cervical, the anterior width is 7cm, its height 10cm; and there is no ventral keel or hint of an hypapophysis.), but it’s not clear from the SOM of your paper what these measurements are for the new specimen. Given this is an important detail — though one doesn’t doubt Sigilmassasaurus brevicollis is a spinosaur if the data is strong enough — it is hard to see how Sigilmassasaurus brevicollis and Spinosaurus aegyptiacus (restricting this argument to the holotype) are synonyms.
      NB: the vertebra is laterally crushed, but it is not clear from Stromer’s description if this affects the centrum substantially, or at all, though he gives the centrum width as “>7” and not actually merely 7cm, suggesting it is; this, however, is not grounds to dismiss the material, as the vertebrae differs in other degrees (including absence of a ventral keel in the posterior cervcials through anterior dorsals, a feature present in Baryonyx walkeri.

      5. Finally, the use of von Stromer over any other name. I’m actually not sure where this started. I’d been using von Stromer for some time, and the reference for it goes back a ways. For example, sources in German at the time of his living used the name “Ernst von Stromer-Reichenbach” whereas others used “Ernst von Stromer,” and even have references to his son, “Wolfgang von Stromer.” It was clear that the use of von prefixing the paternal name was part of the honorific, rather than the locative “von Reichenbach.” I can alter the name convention for the sake of disambiguation, but so far few have complained, or confuse the name with whom I’m speaking of. In paleontology, there was only one “Ernst Stromer,” von or otherwise.

  9. Nizar says:

    Hi,

    Stromer is pretty clear about the association of the B material. They were found in very close association, and he noticed the same thing we did (reduced hind limb elements). Regarding your other points: fitting all of the information into a Science paper is impossible. Our forthcoming detailed description is going to address many other aspects of our research. If you are interested in reconstructing the animal or commenting on the biology of the animal, please do not pay too much attention to some of the images and CGI out there – the Science paper and our upcoming papers should remain the only sources for scientific questions.

    Best regards,

    Nizar

  10. coelophysis says:

    fourth trochanter is not reduce . but the tibia is bigger than the femur its clear won is a juvenile or the other is another dinosaur or tibia is missing for the stumpy small leg spinosaurus and clearly paddle swiming does not hold water because that not spinosaurus tibia and ceratosaurus allso has crocodilian tail and bipedal clearly swim like a croc does not need paddle leg feature ceratosaurus leg is the same as 3 finger dino carnosaur and the finger bone does not have claw and the finger is spinosauridae like. i doubt it walk on knuckle quadrapedal all theropod has some quadrupedal movement allthou it was awful just mostly a launching feature to assit a bipedal attack a crouching attack feature .the head killer dino there finger are allmost the same size like compsognathus or the reduce first finger of limusaurus .on the pterosaur nose of spinosaurus it still has the hybrid skull a mix of false gharial dog like skull of dwarf caiman nile crocodile size teeth it mite use it to make the snout stronger a bite force feature like the small eye of advance theropod dino its not in the crown group that lead to mesoeucrocodylia is just won those dino that hang on like t.rex which both are tyrannosaur . flat wide long feet a webb feature clearly dinosaur is a gator and they are still people holding out on this even after the scipionyx fossil clearly dinosaur is a primtive gator.

  11. Mike from Ottawa says:

    “fitting all of the information into a Science paper is impossible.”

    One of the criticisms has been the choice of an inappropriate forum for a paper making such significant claims based on more material than Science would publish.

  12. Even in Scott Hartman’s corrected model, though, the hindlimbs are proportionally smaller than those of most theropods.

    Given the isotope ratios, I think it’s safe to assume Spinosauridae as a whole was mostly adapted for diving and aquatic pursuit hunting over wading.

    • Hard to dive/pursuit-hunt at that mass without being pelagic. This animal is a wetlands/marsh animal, not a pelagic one. For divers of streams and rivers, you actually need to be very small; there’s not a whole lot of space, even if it’s twice as deep as you are tall. Crocs are an example of a very large-bodied aquatic predator, which prey on terrestrial and aquatic animals. Crocs are not osteosclerotic. It’s more likely that Spino was compensating for remaining terrestrially bipedal, but as there are no extant analogues for this type of animal, we’re kinda winging it here.

      • Well, gharials, river dolphins (such as extinct iniioids such as Saurocetes), giant otters and several others have managed to become aquatic pursuit predators in freshwater environments at large sizes.

        Things like Spinosaurus most likely don’t have a direct equivalent anywhere else, but I do think they’re ecologically compared to other large endothermic coastoal/lacustrine swimmers such as otters and primitive whales.

  13. coelophysis says:

    spinosauridae teeth was simular to the nile crocodile design to crush large land animal bone and they have joint in the jaw to swallow large prey allso found in pterosaur probaly the same joint found in sphenosuchian and modern crocodilian and the nile crocodile hunt a lot on land too and gator too there has been attack on human on land by gator the skull is not design to only eat fish it is nothing like the gharial there teeth are mostly the same size they are missing some skull feature. spinosauridae is a mix between long snout crocodilian skull and the most land crocodilian the dwarf caiman its more dog like there shape of skull is stronger than modern crocodilian but are missing the feature for strong bite force there skull is really not same as modern crocodilian. adult smooth fronted dwarf caiman rarely ever found in water some scientist want to get it out of aquatic list it is design for land there is no webbing it has dinosaur tail and a short snout it was a awful swimer very bad in deep water the shallow water simi aquatic compsognathus allso has dinosaur tail very long tail they swim different from modern dinosaur the crocodilian some thing work they have crocodilian tail now. and the duck bill dinosaur start it out with dinosaur tail ornithopod duck bill dinosaur have crocodilian tail. spinosauridae probaly is like the asian water monitor lizard lifestyle when there is a lot food they were the first mesoeucrocodylia the true crocodilian the advance spinosauridae probaly are just a better swimer with the same lifestyle the phytosaur nose probaly just a bite force feature like how modern crocodilian got rid of that dinosaur hole in the skull it is reduce in all spinosauridae and spinosaurus nose is reduce and they are not in the crown group that lead to modern crocodilian they are just like t.rex just hanging on from a primtive line spinosaurus could not evolve there skull fast like modern crocodilian you see that kind of thing in other primtive animal like how crocodile has those pterosaur protowing batman arm scale skin not found in the advance crocodilian the gator. if it is going the very aquatic way why is the skull like a land crocodilian it is clearly evolving with things like a crocodilian tail.

  14. Also, I should probably link to their reply, which Mark Witton seems to find reasonable:

    http://markwitton-com.blogspot.de/2014/09/the-spinosaurus-hindlimb-controversy.html?spref=tw

  15. coelophysis says:

    all those cliam small legs = aquatic not true in dinosaur like limusaurus and baryonyx spinosauridae. limusaurus legs was bigger than carnotaurus and they are in the same group it was clearly aquatic with reduce finger the claws they were not sharpe and clearly was not a gasping anima l it was head killer with no teeth fish eating feature and long neck very different from carnotaurus . limusaurus clearly use arm to assit a bipedal attack with small first finger it had crouching attack like all theropod .baryonyx had unusual large legs and clearly it was aquatic very flat crocodilian skulll nose on top of the skull point to the sky raise eye . long snout of baryonyx because they were not good swimer like modern crocodilian they had dinosaur tail but clearly they got better with modern crocodilian and spinosaurus . baryonyx like all spinosauridae there snout was too thin like long thin snout like the false gharial orinoco crocodile gharial all thou it is a stronger shape. than the short snout wide snout crocodilian like gator nile crocodile they have to have a small antorbital fenestrae or there snout mite break when twisting that why all spinosauridae the antorbital fenestrae is reduce it is gone all modern crocodilian the early quadrupedal mesoeucrocodylia had a antorbital fenestrae and that the reason why spinosauridae have hybrid skull it is between false gharial and dwarf caiman skull both skull are design to kill large land animal false gharial is well known as man eater and the dwarf caiman is well known to live a lot on land . gharial skull is design to kill fish and small animal .spinosaurus was a simi aquatic animal probaly simular to nile crocodile lifestyle probaly live more on land you do not grow monster death roll sail hump to only eat fish it is design to kill large land animal they have biggest death roll muscle in mesoeucrocodylia because spinosauridae dinosaur have weak bite compire to modern crocodilian they could not crush bone like modern crocodilian probaly specialize in killing large land dinosaur the more power is to rip out flesh easyly they could not go that deep.they clearly use it on land that why they have ball joint on the sail so they do not die on roll over and lack neural arch like all crocodilian.on the phytosaur nose of spinosaurus phytosaur nicrosaurus has straight femur like dinosaur a land feature most phytosaur has crocodilian femur . likely that whale nose is for bite force reduce nose hole in the skull. baryonyx have large nose hole in the skull its a primtive feature a weak bite force that why modern crocodilian are smaller. spinosaurus probaly is bigger by evidence i see the legs are probaly chimaera juvenile .allso no serrated teeth of spinosaurus a aquatic feature gator allso has that feature and they hunt on land. crocodile is known to have serrated teeth like early quadrupedal mesoeucrocodylia and baryonyx the very fake ziphodont teeth.

  16. Herman Diaz says:

    @Jaime A. Headden

    I have a life appearance question about Spinosaurus & figured you’d be 1 of the best ppl to ask, given how involved you’ve been in “Spinogate”: Is the reconstruction in/on the cover of West’s “Spinosaurus: The Thorn Lizard” ( http://www.amazon.com/Spinosaurus-Thorn-Lizard-Graphic-Dinosaurs/dp/1448852447 ) still plausible/accurate based on what we currently know (excluding Ibrahim et al. 2014 b/c of all the uncertainties surrounding it)? I ask b/c I’d like to use said book in a family program, but want to make sure that it’s still useful for showing what Spinosaurus might have looked like when alive (the key words being “might have”). Many thanks in advance.

    • There’s nothing totally implausible about the reconstruction. I’d say the jaws are pretty okay, though the skin texture is too “obvious”: The tubercular texture is “large” and not at all what would be present. At this resolution, you’d not see the skin detail much at all, and that’s not considering if the integument was pebbly or scaly to begin with, which it may very well have not been.

      But as it stands, the illustration is still plausible.

      • Herman Diaz says:

        I probably know the answer, but just in case, I have the same question about the reconstruction in/on the cover of Bailey’s “Spinosaurus” ( http://www.amazon.com/Spinosaurus-Smithsonian-Prehistoric-Gerry-Bailey/dp/0778718158 ). Again, many thanks in advance.

        P.S. We need more “day in the life” type books about spinosaurs.

        • The models and most depictions are designed to imply texture at a small scale, and so tend to exaggerate relief of pebbly texture. The skin is very … toadlike … in order to imply the reptilian texturing. However, theropod skin was either covered in fine scales (and for an animal this size, they’d be indistinct at that scale) or in fine fuzzy integument/feathers.

          • Herman Diaz says:

            1 more thing: Which of the aforementioned reconstructions is more plausible/accurate in terms of both text & paleoart based on what we currently know (again, excluding Ibrahim et al. 2014)? Put another way, which of the aforementioned books would be better to use in a family program that involved reading the book to families & showing them the pictures? Again, many thanks in advance.

          • I haven’t read any of these, so cannot say which is the best. If you want to follow a really good resource on texturing, Julius Csotonyi’s new artbook (available here) is a WONDERFUL reference.

  17. Alex says:

    I found certain aspects of Ibrahim et al. 2014 to be rather sloppy. Isn’t stating your measuring technique an important part of scientific paper? Why not make it a main part of the paper and have some other less critical part be included in the monograph? There’s also the fact that neural spine height was not reported and quadrupedalisim was based the proportions and not actual facts. In fact their “knuckle-walking” animation was not made available for third-party testing.

    I’ve also recently been told that Hartman is collaborating on a response paper. Apparently the paper will place Spinosaurus back on two legs.

  18. coelophysis says:

    i doubt it had red skin the skin would look like a turtle, armadillosuchus , aetosaur. spinosaurus like early quadrupedal mesoeucrocodylia did not have centra monster vertebrae ball joint so they can not stop pressure on a roll over like some quadrupedal mesoeucrocodylia and modern crocodilian that why they skin rows of armo croc bum skin have to be that wide to help pressure on a roll over and lack of neural arch allso help and that why modern crocodilian have small rows of croc bums the centra ball joint is allso use for better swimming and run faster. .and there is no sail its a hump the large neural spine sail bone it is for the large death roll muscle all crocodilian have large sail neural spine like spinosauridae its part of the death roll system it move other muscle pull it up back when they roll over and other part of death roll system the fully secondary bony palate its in the skull those are main feature in crocodilian that why they know spinosauridae is a crocodilian a mesoeucrocodylia a very primtive crocodilian.. no theropod had feather its a scam by tabloid journalism . the none mesoeucrocodylia dinosaur like t.rex and allosaurus are precurser to mesoeucrocodylia all of them lead to the powerful bite force of modern crocodilian there is no link between dinosaur and birds. there closes reltive is the turtle dinosaur is a very primtive crocodilian that why you see spinosaurus with cingulum sensory dot skull snout and sensory dot skin a crocodilian feature and the crocodilian have a lacrimal foramen hole not found in coelophysis it is found in all 3 finger dinosaur allso share lack of postfrontal bone and other feature. the meterite did not kill most dinosaur it was another dinosaur did it mesoecrocodylia that how nature work the better won survive its a lie that dinosaur are dead. crocodilian are like a snake with legs very dangerous animal that why they are alive the last surviving dinosaur.

  19. coelophysis says:

    i am not trolling that is science data i got from the web from scientist report and i talk with scientist on the net. they even help me with the report i not making things up any won can find these things on the web with google search. . the search for dinosaur is over they know that from the 80s when they found mostly complete skull of baryonyx that show it was a mesoeucrocodylia and they know what happen to rest of dinosaur they even know that from the 70’s with ornithosuchus hybrid ankle and gator juvenile legs are bigger than the adult gator just like predator theropod dinosaur you just can look at the living crocodilian and see the dinosaur link it only have 3 finger claws and it is common for marine reptile to grow there finger back that they lost true evolution they have 3 toe claw and 4 toe like theropod dinosaur the early quadrupedal mesoeucrocodylia had 4 toe claws crocodilian are not primtive they fail every primtive test there sprawling is not link to amphibian and lizard they have a open hip socket it is small the won i saw stage 1 protosuchian have stage 2 like herrerasaurus most dinosaur and bird have stage 3 some are close . and common for reptile to loose there sacral vertebrae bipedal mesoeucrocodylia have 3 sacral from the quadrupedal line. crocodilian are a advance dinosaur with a cingulum teeth not found in these primtive land dinosaur rauisuchian protosuchus sphenosuchian aetosaur they are not crocodilian ancestor only spinosauridae is . all predator thecodont theropod dinosaur have a cingulum teeth those protosuchian type lack cingulum and the sensory dot skin that found in every 3 finger dinosaur and crocodilian .only won is trolling is lieing badit scientist and respectble tabloid media curupth media that is keep these data from the public .as for mister knuckle walk they are a lot of quadrupedal dinosaur none of them walk on there knuckle and all of them came from a theropod. quadrupedal evolution were common in dinosaur time there walk are diverse like modern crocodilian like how gharial can not do the high walk all them have small arm large leg like theropod its impossible for spinosaurus to have those small feet with a large fourth trochanter with the tibia bigger than the femur its has to reduce the fourth trochanter like compsognathus likely has the same femur as rest of spinosauridae and fossil is a chimaera and spinosaurus is biggger. allso has a gasping hand it was bipedal. and crocodilian the first thumb claw is biggest like theropod dinosaur the rest is simular too.it is not just the skull alone that is simular they share many other feature.

  20. Alex says:

    Since everyone was focused on the legs, no one bothered to look at the other controversial part of the new reconstruction: the sail.
    Based on the photos on Cau’s website, the “neotype’s” neural spines don’t give any indication of the sail’s shape. In fact Ibrahim’s sail shape may go against what Stromer found (according to one source anyway).

    • I think even the authors are aware that the sail is, for them, mostly hypothetical. It’s a little odd how closely their various depictions go to portray the sail in that way, but that’s the way of art. Many other artists have adopted that sail model as well. This wasn’t much of an issue for me, so I didn’t make much about it.

  21. Pingback: A Look Back at the Bite Stuff, 2014 Edition | The Bite Stuff

  22. Pingback: Pale Spinos–Sigilmassasaurus | The Bite Stuff

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s