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09-09-2020, 06:34 AM( This post was last modified: 09-09-2020, 06:36 AM by tigerluver )
(09-09-2020, 02:30 AM)DinoFan83 Wrote:
(09-09-2020, 12:43 AM)GuateGojira Wrote:
(06-13-2020, 04:37 PM)DinoFan83 Wrote: Here's a quote from SpinoInWonderland regarding the most recent information on Spinosaurus' size. It should also be noted that due to the tail change, Spinosaurus is a bit shorter than otherwise thought. Scaled 132% from the neotype in Ibrahim et al. 2020, MSNM v4047 is 14.4 meters instead of 15+ for instance. This also affects the other specimens:
"Ibrahim et al. (2020) has a volumetric estimate for the neotype, at 3864 litres. Using a mean density of 0.95 for Spinosaurus gives a mass estimate of ~3.67 tonnes. Scaling up to MSNM v4047 (32% greater dimensions as per Ibrahim et al. 2014) yields about ~8.44 tonnes. It has been argued that the chest of the new reconstruction is too deep, but then the scapulacoracoid is also placed too far back at the chest - these might cancel each other out. Henderson (2018) got a mass estimate too low as the chest they modellled for Spinosaurus was way too narrow than was indicated by the known material."
Now I think a density of 1 is probably more likely as the majority of aquatic animals tend to be neutrally buoyant (EG crocodiles, which converge a lot on Spinosaurus).
Assuming that density, we get:
~3.86 tonnes for the neotype (~10.9 meters)
~8.89 tonnes for MSNM v4047 (scaled up 32%, 14.4 meters)
~9.67 tonnes for NHMUK R-16421 (~14.81 meters), following the discrepancy between it and the neotype that SpinoInWonderland got (link)
~13.66 tonnes for NMC 41852 (~16.62 meters), following what SpinoInWonderland restored for the neotype (51 cm humerus) scaled to the restored size of NMC 41852 fit into the humerus of the Baryonyx holotype (77.7 cm in this image given a length of 46.3 cm for the humerus of the Baryonyx holotype).
Going by this, the average size of the 3 Spinosaurus adults we have seems to be ~15.37 meters and ~10.74 tonnes. That's definitely in pre-2014 Spinosaurus territory, so it looks to me as though Spinosaurus was never really downsized but just got a new look.
Interesting calculations, but the official values at this moment are up to 15-16 meters long and up to 7 tons in the biggest specimen, check these articles:
I think a few things should be noted regarding Donald Henderson's model:
-It had assumed that Spinosaurus was pneumatic when it was in fact not; Ibrahim et al. 2014 even stated the bones to be of very high density and with no pneumaticity whatsoever. So not only is the theory about Spinosaurus being highly terrestrial most likely bunk, the wrongly assumed pneumaticity underscores the mass of the animal quite unnecessarily.
-The ribcage on Henderson's model is apparently way too narrow given the known material. This is what SpinoInWonderland has told me, and given what the dorsal view from Ibrahim et al. 2020 looks like compared to Henderson's model I am inclined to agree with him. I apologize if the resolution on this is too low but here are the dorsal views compared from Ibrahim (2020) and Henderson (2018):
*This image is copyright of its original author
It should be beyond clear that judging from Ibrahim's model, Henderson's model is SUBSTANTIALLY too narrow - it's literally about 1/2 the width at the torso and this underscores the mass of the animal quite a bit.
-I would not consider Henderson's model to be as accurate as Ibrahim et al. 2020 in terms of its overall anatomy. In addition too the very narrow torso and the unnecessary pneumaticity, the torso on the model from Henderson is much shallower than the new model from Ibrahim, nor does it have the new tail added onto it. All of this is underscoring the model's mass.
By the way, even if we take Henderson's estimation of 7 tonnes for MSNM v4047 at face value (which is a poor choice when Ibrahim's model is available considering what I went over above), it still does not factor in NHMUK R-16421 nor NMC 41852, both of which are most likely larger. Using the discrepancies in my above post on Spinosaurus' size, NHMUK would be about 8.12 tonnes, and NMC (although tentative until we find more Spinosaurus humeri) would be 10.55 tonnes.
As for that National Geographic article you linked, I am afraid that when I clicked on it the page said it no longer existed. However I suspect they are referring to the outdated model from Ibrahim (2014) that suggested 6 to 7 tonnes instead of the new model from the 2020 study in their article.
By the way, if you didn't already see this, there is something to consider:
*This image is copyright of its original author
Nizar Ibrahim himself supports masses of 10-12 tonnes for Spinosaurus in light of the new and more accurate model, and these sizes are easily replicated when scaling NHMUK R-16421 and NMC 41852. The old 6 to 7 tonne estimations are outdated.
So if you want to stick with the old 7 tonne estimations I suppose I can't stop you, but considering everything above the double digit tonnage is almost certainly more accurate.
I suppose the way to assess the accuracy of these models is the pubis vs skull measurement (I think it was a quadrate that is available?) on FSAC-KK 11888. The Henderson model has a much narrower pubis relative to the head than the Ibrahim et al. model.
On a tangent, there's supposedly a Spinpsaurus arm sitting in a lab now. Hoping this is true and we find out whether this animal was quadrupedal or bipedal, or both.
09-09-2020, 07:02 AM( This post was last modified: 09-09-2020, 07:30 AM by DinoFan83 )
As for the pubis vs skull measurement, both of the models appear very similar in that regard, as well as in skull/quadrate length to pelvic depth ratios; the width of the pubis is not really relevant so much as its length so if either has a pubis that is too thick or thin it does not affect the mass with correction. It seems moreso to me that the new model is more massive due to the above reasons (wider torso, lesser pneumaticity, bigger tail, and so on).
Regarding that forelimb, I have heard about it as well, and the anteroposterior view of the humeral shaft is pretty much identical to that of NMC 41852, so once it gets described it should be helpful to scale NMC 41852.
However, Spinosaurus would have almost certainly been bipedal. In addition to theropods being unable to pronate their hands, here is a quote from Jaime Headden that explains that well:
"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 Spinosaurusfaster 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."
(09-09-2020, 07:02 AM)DinoFan83 Wrote: As for the pubis vs skull measurement, both of the models appear very similar in that regard, as well as in skull/quadrate length to pelvic depth ratios; the width of the pubis is not really relevant so much as its length so if either has a pubis that is too thick or thin it does not affect the mass with correction. It seems moreso to me that the new model is more massive due to the above reasons (wider torso, lesser pneumaticity, bigger tail, and so on).
Regarding that forelimb, I have heard about it as well, and the anteroposterior view of the humeral shaft is pretty much identical to that of NMC 41852, so once it gets described it should be helpful to scale NMC 41852.
However, Spinosaurus would have almost certainly been bipedal. In addition to theropods being unable to pronate their hands, here is a quote from Jaime Headden that explains that well:
"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 Spinosaurusfaster 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."
Sorry, I don't follow on the proportions. What osteological measurements have resulted in the Ibrahim et al. reconstruction being so much wider in the lateromedial axis? The wider torso has to be a function in part of the pelvic girdle (lateromedial diameter) as we don't have a scapula one would think. IIRC, the centrums of spinosaurus were quite thin as well compared to say T. rex.
09-09-2020, 08:26 AM( This post was last modified: 09-09-2020, 08:28 AM by GuateGojira )
(09-09-2020, 02:30 AM)DinoFan83 Wrote: I think a few things should be noted regarding Donald Henderson's model:
-It had assumed that Spinosaurus was pneumatic when it was in fact not; Ibrahim et al. 2014 even stated the bones to be of very high density and with no pneumaticity whatsoever. So not only is the theory about Spinosaurus being highly terrestrial most likely bunk, the wrongly assumed pneumaticity underscores the mass of the animal quite unnecessarily.
-The ribcage on Henderson's model is apparently way too narrow given the known material. This is what SpinoInWonderland has told me, and given what the dorsal view from Ibrahim et al. 2020 looks like compared to Henderson's model I am inclined to agree with him. I apologize if the resolution on this is too low but here are the dorsal views compared from Ibrahim (2020) and Henderson (2018):
*This image is copyright of its original author
*This image is copyright of its original author
It should be beyond clear that judging from Ibrahim's model, Henderson's model is SUBSTANTIALLY too narrow - it's literally about 1/2 the width at the torso and this underscores the mass of the animal quite a bit.
-I would not consider Henderson's model to be as accurate as Ibrahim et al. 2020 in terms of its overall anatomy. In addition too the very narrow torso and the unnecessary pneumaticity, the torso on the model from Henderson is much shallower than the new model from Ibrahim, nor does it have the new tail added onto it. All of this is underscoring the model's mass.
By the way, even if we take Henderson's estimation of 7 tonnes for MSNM v4047 at face value (which is a poor choice when Ibrahim's model is available considering what I went over above), it still does not factor in NHMUK R-16421 nor NMC 41852, both of which are most likely larger. Using the discrepancies in my above post on Spinosaurus' size, NHMUK would be about 8.12 tonnes, and NMC (although tentative until we find more Spinosaurus humeri) would be 10.55 tonnes.
As for that National Geographic article you linked, I am afraid that when I clicked on it the page said it no longer existed. However I suspect they are referring to the outdated model from Ibrahim (2014) that suggested 6 to 7 tonnes instead of the new model from the 2020 study in their article.
By the way, if you didn't already see this, there is something to consider:
*This image is copyright of its original author
*This image is copyright of its original author Nizar Ibrahim himself supports masses of 10-12 tonnes for Spinosaurus in light of the new and more accurate model, and these sizes are easily replicated when scaling NHMUK R-16421 and NMC 41852. The old 6 to 7 tonne estimations are outdated.
So if you want to stick with the old 7 tonne estimations I suppose I can't stop you, but considering everything above the double digit tonnage is almost certainly more accurate.
What are you talking about, all models of Spinosaurus, all the draws and reconstructions, all aknowledge that Spinosaurus was thin, it was slender and do not had a large ribcage, is not near the large Carcharodontosaurids and definitelly not as large as T. rex.
I was about to discuss the details but when you mentioned Spinoinwonderland again I saw that all this will be just a joke. I think that is futile to discuss the outdated and weird conclutions of a "Spino-fan" that constantly reject all the information in favor of the T. rex.
The opinion of Ibrahim is just that, an opinion, so while he know the fossils of the Spinosaurus, we need a good and accurate study about its body mass to take his word. Let's remember that his conclution of the cuadruped was not quite correct, so he is good but not perfect.
09-09-2020, 06:12 PM( This post was last modified: 09-10-2020, 04:17 PM by DinoFan83 )
For both tigerluver's points and GuateGojira's points I think a few things should be noted.
Regarding the ribcage (both): I'm not 100% sure exactly if there were any specific osteological measurements that led Ibrahim to give the model a wider torso but that wider torso is more coherent with what both the mounted skeletons and Andrea Cau's attempt at articulating spinosaur ribs will show us; a width to depth ratio of at least 1 to 1. That's quite more than Henderson (2018), which was something like 64.3% as wide as its deepest point, so it could be that Ibrahim took a cue from those while working on the new model or was simply able to replicate the results both the mounts and Cau got when trying his hand at rib articulation. Spinosaurus isn't tanker like or super-wide to the degree of something like an ankylosaur, but it is fairly rotund. I have asked SpinoInWonderland about the specifics and will probably either also email Ibrahim or sign up for Reddit and ask him there about the width. I'll get back to this thread with the answer when either responds.
Regarding how wide/robust Spinosaurus was (GuateGojira): Yes, it's not as wide as wider dinosaurs like carcharodontosaurids or tyrannosaurids but spinosaurids in general tend to be fairly rotund and barrel chested in their torsos. The mounted skeletons as well as Cau's attempt for articulation of the ribs do show it's circular in cross section or perhaps a bit wider. It doesn't have an angelfish like cross section like Henderson's model may suggest.
Regarding the accuracy of Ibrahim's conclusion (GuateGojira): Yes, his assumption for a quadrupedal spinosaur was not correct, but I see more reason to trust the width of his model as opposed to Henderson given that it falls more in line with what several independent attempts for rib articulation have arrived at. It's best to look at research conclusions on a case by case basis - just because some are wrong does not mean that is the case with others. And in this case, not only is the torso width more in line with other attempts, the masses of 10-12 tonnes are easily replicated when scaling some specimens, as previously stated.
Regarding that National Geographic article (GuateGojira): I clicked on it again and as it turns out, you are right, it does exist. However, they make no citation to the 2020 study for the mass, which reaffirms my suspicion that they're using the old 2014 model for the mass as not only is a mere 7 tonnes not coherent with the new model, that figure is very widespread and well known so it'd be easy for them to just put it in the article.
And finally, regarding SpinoInWonderland (GuateGojira):
Quote:I was about to discuss the details but when you mentioned Spinoinwonderland again I saw that all this will be just a joke. I think that is futile to discuss the outdated and weird conclutions of a "Spino-fan" that constantly reject all the information in favor of the T. rex.
That's not what he is at like at all these days, what you're thinking of is really, really old stuff back from 2012. He has since then changed his viewpoints, and just because he gets larger sizes than other people for some theropods does NOT mean he rejects information in favor of Tyrannosaurus nor does it mean his conclusions are outdated and weird. His methods and works are easily explainable and defensible, and whatever you should have an issue with, let me know. I think either I can explain it sufficiently or I can ask SpinoInWonderland.
By the way, if this has to do with his username, the 'Spino' in it does NOT come from Spinosaurus but rather Spinophorosaurus. I can see how you would think he is a Spinosaurus fan by reading his name at face value but not only is that not what he is, the name doesn't even have anything to do with Spinosaurus at all.
One last thing, based on some personal communication with SIW himself, agreeing to disagreeing if we cannot agree and if you don't want to talk to him may be best. I have absolutely no issue to continue this but if turns out we cannot agree and if you don't want to talk to SIW about this, we may have to agree to disagree.
09-09-2020, 11:16 PM( This post was last modified: 09-09-2020, 11:24 PM by tigerluver )
Another misconception, Spinosaurus as a quadruped is not exactly disproven. We don't have the forelimbs or the pectoral girdle. Compared to the 2014 model, in the 2020 model the center of gravity just slightly shifts backward given the now heavier tail. Therefore, they reconstructed it as a biped. I checked that supposed Spinosaurus arm again and it's probably a composite. So it seems unfortunately we still don't know much of the front half of Spinosaurus. It would take just a slightly heavier head, wider pectoral girdle, or some longer cervical spines to tip the 2020 model back to a quadrupedal position. I am not saying Spinosaurus was quadrupedal, but I am trying to illuminate this "disproven" misconception as most don't seem to understand the methods and the reason for the change.
09-10-2020, 01:02 AM( This post was last modified: 11-11-2020, 09:26 PM by DinoFan83 )
As it turns out, correcting the model from Henderson (2018) gets a surprisingly large animal well in line with the estimations from Ibrahim (2020).
The model was 7 tonnes as-is, but not only is it only around 63.4% as wide as the deepest parts of the torso (upon closer inspection), it is also too pneumatic with a density of 0.833 when it should have been around 1, and it doesn't have the new tail which would have been around 1.5 times the mass of the old one judging by the neural spine depth. The exact torso mass is not listed in the study so to tentatively estimate the corrected version, I'll assume the torso and tail in Henderson's model takes up roughly the same percentage of the animal's mass as SpinoInWonderland's old Spinosaurus (which was only apparently too small-headed and too elongated overall, for proportional size of each body part it should be fine).
Pneumaticity correction: Changing the pneumaticity from 0.833 to 1, Henderson's model goes to 8.4 tonnes.
Torso widening: Widening the torso about 57.7% (100/63.4=about 57.7) using the assumption that it was proportionally similar to SIW's old GDI (meaning a torso slightly over 55.7% of total mass), it goes up to 11.1 tonnes.
Tail mass increase: Increasing the tail mass 50% assuming proportional similarity to the GDI (meaning a tail about 20.8% of total mass), it goes up to 12.26 tonnes. This is not statistically distinct from what the new model (10.93 meters, 3864 liters) gives at a 16 meter length.
All in all, this compares very favourably with the sizes for NHMUK R-16421 and NMC 41852 that I have outlined earlier in this thread. Which really isn't surprising.
(09-10-2020, 01:02 AM)DinoFan83 Wrote: As it turns out, correcting the model from Henderson (2018) gets a surprisingly large animal well in line with the estimations from Ibrahim (2020).
The model was 7 tonnes as-is, but not only is it only around 63.4% as wide as the deepest parts of the torso (upon closer inspection), it is also too pneumatic with a density of 0.833 when it should have been around 1, and it doesn't have the new tail which would have been around 1.5 times the mass of the old one judging by the neural spine depth. The exact torso mass is not listed in the study so to tentatively estimate the corrected version, I'll assume the torso and tail in Henderson's model takes up roughly the same percentage of the animal's mass as SpinoInWonderland's old Spinosaurus (which was only apparently too small-headed and too elongated overall, for proportional size of each body part it should be fine).
Pneumaticity correction: Changing the pneumaticity from 0.833 to 1, Henderson's model goes to 8.4 tonnes.
Torso widening: Widening the torso about 57.7% (100/63.4=about 57.7) using the assumption that it was proportionally similar to SIW's old GDI (meaning a torso slightly over 55.7% of total mass), it goes up to 11.1 tonnes.
Tail mass increase: Increasing the tail mass 50% assuming proportional similarity to the GDI (meaning a tail about 20.8% of total mass), it goes up to 12.26 tonnes.
All in all, this compares very favourably with the sizes for NHMUK R-16421 and NMC 41852 that I have outlined earlier in this thread. Which really isn't surprising.
Good breakdown, but now we just to get the osteological basis to make this concrete.
The new FSAC-KK-11888 was proposed to be around 4000 kg depending on the density used. Dal Sasso and colleagues have gone with MSNM v4047 being 32.5% larger in osteological dimensions than FSAC-KK-11888, at least in their past publications. (I've gotten this from personal communication but it might be published out there. I know Persons et al. 2019 use this value to extrapolate the femoral circumference of MSNM v4047 from FSAC-KK-11888). Scaling up via isometry (multiply 4000 kg by 1.325^3), we get 9300 kg. I'd like to know the basis for the higher estimate then. Perhaps they now consider the size difference even greater?
Yes, I'd say it's plausible that the size difference could be even greater than 32.5%. I'll need to dig up exactly where this was but I believe that I read somewhere that theropod1 on Deviantart was able to obtain discrepancies of 40 to 45 percent between the neotype and the Milan rostrum, which the >12 tonne MSNM V 4047 fits well into compared to the 4 tonne neotype. This could be one of those cases where a specimen is bigger relative to another than the most popular size estimation.
Largest specimens of Spinosaurus and Carcharodontosaurus (NMC 41852 and SGM-DIN 1), both skeletals by SpinoInWonderland.
Spinosaurus is scaled to 77.7 cm humerus and is 13+ tonnes, while Carcharodontosaurus is scaled to 13.23 meters TL and is 9+ tonnes. (Although NMC 41852's size estimation here is tentative until there are more Spinosaurus humeri found), I do think that Spinosaurus would have been more than capable of defending itself on land given its substantial size and strength advantage.
Would I be able to see a source for that weight? Given what's been posted in this thread I don't think weights much above 13-14 tonnes to be realistic for any Spinosaurus specimens we have.
Would I be able to see a source for that weight? Given what's been posted in this thread I don't think weights much above 13-14 tonnes to be realistic for any Spinosaurus specimens we have.
Greetings Dino,I forgot the source sorry.But the biggest weight I have ever read is 22,000.I think in a youtube video.
09-19-2020, 06:47 PM( This post was last modified: 09-19-2020, 08:31 PM by BorneanTiger )
(09-09-2020, 06:34 AM)tigerluver Wrote:
(09-09-2020, 02:30 AM)DinoFan83 Wrote:
(09-09-2020, 12:43 AM)GuateGojira Wrote:
(06-13-2020, 04:37 PM)DinoFan83 Wrote: Here's a quote from SpinoInWonderland regarding the most recent information on Spinosaurus' size. It should also be noted that due to the tail change, Spinosaurus is a bit shorter than otherwise thought. Scaled 132% from the neotype in Ibrahim et al. 2020, MSNM v4047 is 14.4 meters instead of 15+ for instance. This also affects the other specimens:
"Ibrahim et al. (2020) has a volumetric estimate for the neotype, at 3864 litres. Using a mean density of 0.95 for Spinosaurus gives a mass estimate of ~3.67 tonnes. Scaling up to MSNM v4047 (32% greater dimensions as per Ibrahim et al. 2014) yields about ~8.44 tonnes. It has been argued that the chest of the new reconstruction is too deep, but then the scapulacoracoid is also placed too far back at the chest - these might cancel each other out. Henderson (2018) got a mass estimate too low as the chest they modellled for Spinosaurus was way too narrow than was indicated by the known material."
Now I think a density of 1 is probably more likely as the majority of aquatic animals tend to be neutrally buoyant (EG crocodiles, which converge a lot on Spinosaurus).
Assuming that density, we get:
~3.86 tonnes for the neotype (~10.9 meters)
~8.89 tonnes for MSNM v4047 (scaled up 32%, 14.4 meters)
~9.67 tonnes for NHMUK R-16421 (~14.81 meters), following the discrepancy between it and the neotype that SpinoInWonderland got (link)
~13.66 tonnes for NMC 41852 (~16.62 meters), following what SpinoInWonderland restored for the neotype (51 cm humerus) scaled to the restored size of NMC 41852 fit into the humerus of the Baryonyx holotype (77.7 cm in this image given a length of 46.3 cm for the humerus of the Baryonyx holotype).
Going by this, the average size of the 3 Spinosaurus adults we have seems to be ~15.37 meters and ~10.74 tonnes. That's definitely in pre-2014 Spinosaurus territory, so it looks to me as though Spinosaurus was never really downsized but just got a new look.
Interesting calculations, but the official values at this moment are up to 15-16 meters long and up to 7 tons in the biggest specimen, check these articles:
I think a few things should be noted regarding Donald Henderson's model:
-It had assumed that Spinosaurus was pneumatic when it was in fact not; Ibrahim et al. 2014 even stated the bones to be of very high density and with no pneumaticity whatsoever. So not only is the theory about Spinosaurus being highly terrestrial most likely bunk, the wrongly assumed pneumaticity underscores the mass of the animal quite unnecessarily.
-The ribcage on Henderson's model is apparently way too narrow given the known material. This is what SpinoInWonderland has told me, and given what the dorsal view from Ibrahim et al. 2020 looks like compared to Henderson's model I am inclined to agree with him. I apologize if the resolution on this is too low but here are the dorsal views compared from Ibrahim (2020) and Henderson (2018):
*This image is copyright of its original author
It should be beyond clear that judging from Ibrahim's model, Henderson's model is SUBSTANTIALLY too narrow - it's literally about 1/2 the width at the torso and this underscores the mass of the animal quite a bit.
-I would not consider Henderson's model to be as accurate as Ibrahim et al. 2020 in terms of its overall anatomy. In addition too the very narrow torso and the unnecessary pneumaticity, the torso on the model from Henderson is much shallower than the new model from Ibrahim, nor does it have the new tail added onto it. All of this is underscoring the model's mass.
By the way, even if we take Henderson's estimation of 7 tonnes for MSNM v4047 at face value (which is a poor choice when Ibrahim's model is available considering what I went over above), it still does not factor in NHMUK R-16421 nor NMC 41852, both of which are most likely larger. Using the discrepancies in my above post on Spinosaurus' size, NHMUK would be about 8.12 tonnes, and NMC (although tentative until we find more Spinosaurus humeri) would be 10.55 tonnes.
As for that National Geographic article you linked, I am afraid that when I clicked on it the page said it no longer existed. However I suspect they are referring to the outdated model from Ibrahim (2014) that suggested 6 to 7 tonnes instead of the new model from the 2020 study in their article.
By the way, if you didn't already see this, there is something to consider:
*This image is copyright of its original author
Nizar Ibrahim himself supports masses of 10-12 tonnes for Spinosaurus in light of the new and more accurate model, and these sizes are easily replicated when scaling NHMUK R-16421 and NMC 41852. The old 6 to 7 tonne estimations are outdated.
So if you want to stick with the old 7 tonne estimations I suppose I can't stop you, but considering everything above the double digit tonnage is almost certainly more accurate.
I suppose the way to assess the accuracy of these models is the pubis vs skull measurement (I think it was a quadrate that is available?) on FSAC-KK 11888. The Henderson model has a much narrower pubis relative to the head than the Ibrahim et al. model.
On a tangent, there's supposedly a Spinpsaurus arm sitting in a lab now. Hoping this is true and we find out whether this animal was quadrupedal or bipedal, or both.
Just a comment here, if you don't mind. With different scientists working with different methods, you'll get different theories or models. That's what I've learnt after a discussion that I had with Guate about the relationship (whether close or distant, physical or genetic) between prehistoric "mega-toothed" sharks like the Megalodon (which was traditionally treated or depicted as an oversized, prehistoric version of the GW (great white shark, Carcharodon carcharias), even though the dentition of the Megalodon appears to be more similar to that of a mako shark (genus Isurus) than that of a GW, and is treated as belonging to another genus (at least Carcharocles, or more recently, Otodus)), and other sharks from the prehistoric (like Cretolamna appendiculata, which has a remarkably preserved fossil (by the standards of sharks, which normally don't leave fossils behind, because they don't have bones), and is considered to be more closely related to the Megalodon than the GW) and modern ages (like the GW and mako sharks): https://wildfact.com/forum/topic-megalod...pid=126975
