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Spinosaurus News ~
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 (09-19-2020, 05:17 PM)cheetah Wrote:(09-17-2020, 04:05 PM)DinoFan83 Wrote: @ Funny, only now can I see and respond to this post. This isn't the first time this has happened; it has also happened with Mstr293 with their very first post (I was quoted in the Giganotosaurus profile thread but could not see it until several weeks later). I suspect that when a member first quotes me in a post, that post isn't visible to me for some days. Anyway, back on topic, YouTube videos tend to be EXTREMELY poor sources for information on dinosaurs, for reasons I hope I don't have to explain. However, if what you meant by 22,000 was 22,000 pounds (10 tonnes), I would say that that is a perfectly reasonable weight for an adult Spinosaurus considering everything I have went over on the previous pages in defense of 10-12+ tonne spinosaurs.
For anyone who's read the debate on pages 6-7 of this thread, this should be a helpful image. Spinosaurus model from Henderson (2018) with the ribcage problem fixed; it now has the ribcage about as wide as the deepest point of the torso and masses >12 tonnes instead of 7. Doesn't have the new tail, but you get the idea.
 *This image is copyright of its original author Also, an important note regarding extrapolations from FSAC-KK 11888 to a >12 tonne MSNM v4047: Aside from the fact that the size discrepancy between the 2 specimens could very well be 40-45 plus percent instead of 32.5% as Ibrahim et al. suggests, we also need to remember that while the neotype is the most complete Spinosaurus thus far, the fact of the matter is that it's still not very complete in and of itself. It could very well be larger than the model from Ibrahim (2020) and scale to a >12 tonne MSNM v4047 with only a 32.5% size increase.
One last thing: I forgot to post these here before, but this should come in handy for both this thread in general and the people who have not seen it before. Spinosaurus skeletals by SpinoInWonderland:
https://www.deviantart.com/spinoinwonder...-827067720  *This image is copyright of its original author Also a good read: https://thesauropodomorphlair.wordpress....-taletail/ 
https://psdinosaurs.blogspot.com/2019/03...%20and%20n
Here is some info on spinosaurus sizes
Hello @DinoFan83 I found the site which says 22,000 kg
https://www.britannica.com/animal/Spinosaurus (10-09-2020, 11:42 PM)cheetah Wrote: https://psdinosaurs.blogspot.com/2019/03...%20and%20n That blog is a very, very poor site. It uses extrapolations from unrelated dinosaurs altogether, ignores preexisting measurements in favor of their own, often faulty measurements, and ignores all bones in favor of 1 or 2 for a length estimate.
https://www.researchgate.net/publication...nosaurines
This is the most recent I could find. Seems it may not be valid. 
11-21-2020, 12:49 AM
( This post was last modified: 11-21-2020, 01:15 AM by tigerluver
Edit Reason: Fixed font color.
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I'd like to contribute towards the new mass measurements, for spinosaurus...
Using supplementary data 2, available we can get some of the values of mass and density values from FSAC KK11888 https://www.nature.com/articles/s41586-020-2190-3#Sec9  *This image is copyright of its original author The question is what value of mass is appropriate to use, it would seem the 3219kg would be, Spinosaurus aegypticus/Sigilmassasaurus (Smyth et al 2020 considers them to be same taxa based on dentition similarity) https://www.sciencedirect.com/science/a ... 7120302068) has been reported to have air sacs in the vertebra (FSAC-KK-7280 (pneumatic foramen and FSAC-KK-18122 known from posterior cervical vertebra with air spaces at the bottom), Lakin et al 2019 Using the improvement of Hendeson's spinosaurus, from the table, a density of 833kgm^3 density is most logical. By using the equations... Mass = Density x Volume Volume = Mass / Volume Specimen FSAC KK11888 Length 10.37m Mass 3219 kg Density 833 kgm3 Volume = 3.86434574m^3 x (3219kg/833 kgm3) MSNM V4047 (largest specimen of spinosaurus) Length: 12.566, despite the common misconception, there is a sort of myth of MSNM v4047's skull length, 1.75m is a overstatement, a revisited measurement indicates 1.5 metres.  *This image is copyright of its original author Here is a direct quote from Therrien et al 2007, ''A note of caution concerns the dimension of the reconstructed Spino- saurus skull. First, the proposed skull restoration (Dal Sasso et al. 2005:fig. 5B) is a composite reconstruction with the front and back halves being from different genera. Because skull shape varies among spinosaurids (i.e., the shape of the rostrum, the relative dimensions of the maxillae and premaxillae, and the shape of posterior region of the skull differ among spinosaurids; Fig. 3), there is potential for overestimating the length of a com- posite spinosaur skull. Second, Dal Sasso and colleagues’ (2005:fig. 5) skull length estimate represents the distance be- tween the premaxilla and the squamosal, which is greater than the measurement (premaxilla-occipital condyle) used in our pre- dictive equations. Therefore, the body length estimate derived above (14.34 m) exceeds what must have been the total body length of the animal. It only takes a skull length (premaxilla- occipital condyle) of 1.50 m, that is, 0.25 m (14%) shorter than originally suggested, to predict a substantially shorter (22% to 31%) total body length of 12.57 m'' According to Ibrahim et al scaling the subadult neotype's skull (112 cm) to 32% larger gives a skull length for MSNV 4047 147.84cm. https://d3qi0qp55mx5f5.cloudfront.net/p ... 1591805883 Hendrickx et al 2016 also agrees with this but slightly exaggerates the skull length to 160cm. https://journals.plos.org/plosone/artic ... 695.ref022 Speaking of Lakin et al, the paper also favours a 12-15m long spinosaurus too. https://www.sciencedirect.com/science/a ... 7118302052 With all of this in mind, using the formula from Therrien 2007, Body Length=1.03161 * 10 ^(0.85673*Log(1.5 metres)+0.93482) This equates to 12.566 metres for a length. Using the equation of square cube law  *This image is copyright of its original author The new volume is 3.86434574m3 x(12.566m/10.37m)^3 6.87592090769 m3 Using Mass = Density 833kgm3 vs Volume (6.87592090769m3) mass = 5727.64211611 kg Just to get a misconception out of the way, Henderson 2018 includes a pneumatic and non-pneumatic spinosaurus https://peerj.com/articles/5409/ Quoting... ''As a test of how sensitive the buoyant Spinosaurus model was to the assumed presence of avian style air sacs and pneumatized bone, an alternate model lacking these features was tried. This model assigned a uniform axial density of 1,000 gm/l from the tip of the tail to the tip of the snout. The limb and sail densities were unchanged, and the same lung was retained. This alternate model can also be thought of as one with a denser skeleton. This model has higher mean density of 918 gm/l and is heavier, 7,160 kg,'' Some may wonder why Campione et al, using the circumference of the femur for Spinosaurus well according to Person's et al 2019 spinosaurus lacked a open medullary cavity that most over theropods have, increasing femora as a result, https://anatomypubs.onlinelibrary.wiley ... 2/ar.24118 (Therrien & Henderson, 2007) mass method overexaggerates theropod mass, in the case of other megatheropods. The only available option is square cube law (isometric scaling) Lakin 2019 also confirms this. ''The disarticulated and fragmentary nature of this material makes it difficult to arrive at robust estimates of body length, and even more difficult to estimate mass given the lack of reliable indicators such as skull length (Therrien & Henderson, 2007), or limb bone dimensions (Campione and Evans, 2011, Benson et al., 2014). However, the proportions and shapes of the vertebrae are very similar to adult material described in previous work (Stromer, 1915, Dal Sasso et al., 2005, Ibrahim et al., 2014b), suggesting a broadly isometric growth pattern for Spinosaurus '' https://www.sciencedirect.com/science/a ... 7118302052 But what if spinosaurus was 14.34 m (overexaggerated length - We know it's not bang on 15 metres because not only because Therrien et al's forumla but also Ibrahim et al 2014 scaling a ''supposed'' 11 metre individual an extra 32% which is 14.5m)? Body Length=1.03161 * 10 ^(0.85673*Log(1.75 or 1.6 metres)+0.93482) Volume = 3.86434574m3 (14.34m/10.37m) ^3 = 10.2185m3 Using Mass = Density 833kgm3 vs Volume 1.75 skull length = 14.34m in length = 10.21 m3 volume = 8504 kg 1.6 skull length = 13.28m in length = 8.11m3 volume = 6760 kg In conclusion the largest spinosaurus specimens were around 5.72 metric tonnes to 6.76 metric tonnes in mass, a 15 metre ong spinosaurus would still be less than 10 tonnes around 9.5. Quote:The question is what value of mass is appropriate to use, it would seem the 3219kg would be, Spinosaurus aegypticus/Sigilmassasaurus (Smyth et al 2020 considers them to be same taxa based on dentition similarity) https://www.sciencedirect.com/science/a ... 7120302068) has been reported to have air sacs in the vertebra (FSAC-KK-7280 (pneumatic foramen and FSAC-KK-18122 known from posterior cervical vertebra with air spaces at the bottom), Lakin et al 2019 May I ask, why do you think those spinosaurid cervicals (that aren't even confirmed to be the same taxon, and if they are, are from an animal much further ontogenetically from the large adults than FSAC-KK 11888 is and therefore may not be a better model) are a better model for density than a reasonably complete skeleton which had its bones histologically analyzed and was found to be completely free of any pneumatization? I would prefer to trust the word of Nizar Ibrahim on Spinosaurus having completely solid bone (and therefore no air sacs with a density of 1 or so), given the difference between the specimens you and him are using to come to conclusions on pneumatization. Not to mention, a density of 0.833 seems too excessively low for the following reasons: -Even sauropods (some of the most pneumatic of all non-avian dinosaurs, with all species known so far having much more postcranial pneumaticity than Spinosaurus) would have been somewhat denser than that. Molina-Pérez & Larramendi (2020) suggest a density of 0.9 for them (page 10). Therefore, I find it difficult to believe that Spinosaurus (which may have had some airsacks in only its neck at most, and could just as well have had none at all) would have a density around 8% lower than animals with very extensive airsacks in both their necks and torsos. -Most other theropods (which had significantly more airsacks than Spinosaurus did) do not seem to have been around the density of 0.833 either. For instance (although his conclusion on this blogpost was almost certainly incorrect for reasons I can explain if you so wish), Scott Hartman has come to a density figure of roughly 0.915 for Giganotosaurus when taking into account the (significantly greater) amount of airsacks in the head, neck, and torso. Molina-Pérez & Larramendi (2016) also support my viewpoint, suggesting an even higher figure of 0.95 (page 11) when taking into account the fact that all tissues save for fat are a good deal denser than water. Therefore I do not see justification for such a low density in Spinosaurus, given its dense bones and the much higher densities of even theropods that had many more airsacks. As stated above, I find a density of 1 or so the most plausible, and that would result in 3,864 kilograms for the new model of the neotype. Quote:MSNM V4047 (largest specimen of spinosaurus) I think you may be interested to know that by superimposing the rostrum on a privately owned complete skull of Spinosaurus, SpinoInWonderland has achieved a skull length of 1.86 meters for MSNM v4047. My assumption is that his reconstruction should hold at least as much as any other if not moreso, since it is bases solely on the complete and undistorted skull of a conspecific, so I don't know whether you have anything that suggests this to be wrong, but 175 cm or more does not seem to be an overestimate to me and in fact seems quite probable. There's also the skull reconstruction of 177 cm by theropod1, which is to my knowledge still accurate. Quote:According to Ibrahim et al scaling the subadult neotype's skull (112 cm) to 32% larger gives a skull length for MSNV 4047 147.84cm. Considering what I have outlined above, would you care to explain how 160 cm is an exaggeration? Also, for what it's worth, the 112 cm skull length figure for FSAC-KK 11888 would result in MSNM v4047 being about 17.1 meters long using the 10.93 meter estimate from Ibrahim et al. 2020 as well as theropod1's skull reconstruction for it. One last thing: Comparing Therrien and Henderson (2007) to the models from Ibrahim is not apples to apples. The formula of the former is based on a much more compact animal (a short tailed tyrannosaurid) as a general basis, and therefore using it as the basis for Spinosaurus length estimates is generally problematic. I find 16 meters (Henderson 2018, corrected model outlined earlier in this thread) to 17.1 meters more likely given that they base on actual conspecifics instead of an unrelated theropod with a completely different lifestyle, etc. Quote:With all of this in mind, using the formula from Therrien 2007, Can you explain how this would hold up compared to the higher estimates given how I have shown that it very likely does not? Quote:Just to get a misconception out of the way, Henderson 2018 includes a pneumatic and non-pneumatic spinosaurus Still too pneumatic if my above sources are anything to go by. The corrected model of this (page 7) is more than 12 tonnes. Quote:Some may wonder why Campione et al, using the circumference of the femur for Spinosaurus well according to Person's et al 2019 spinosaurus lacked a open medullary cavity that most over theropods have, increasing femora as a result, As I have told you before, femoral circumference is not reliable to estimate mass: https://thesauropodomorphlair.wordpress....timations/ Quote:(Therrien & Henderson, 2007) mass method overexaggerates theropod mass, in the case of other megatheropods. What other reasons do you have for preferring such sizes over the new 10-12+ tonne estimates, considering everything I have outlined above? All things considered, I find the much higher length and mass estimates to be much more likely because they are 100% based on Spinosaurus material, assume what seems to be a proper density, and are solely volumetric.
''May I ask, why do you think those spinosaurid cervicals (that aren't even confirmed to be the same taxon, and if they are, are from an animal much further ontogenetically from the large adults than FSAC-KK 11888 is and therefore may not be a better model) are a better model for density than a reasonably complete skeleton which had its bones histologically analyzed and was found to be completely free of any pneumatization? I would prefer to trust the word of Nizar Ibrahim on Spinosaurus having completely solid bone (and therefore no air sacs with a density of 1 or so), given the difference between the specimens you and him are using to come to conclusions on pneumatization.
Not to mention, a density of 0.833 seems too excessively low for the following reasons: -Even sauropods (some of the most pneumatic of all non-avian dinosaurs, with all species known so far having much more postcranial pneumaticity than Spinosaurus) would have been somewhat denser than that. Molina-Pérez & Larramendi (2020) suggest a density of 0.9 for them (page 10). Therefore, I find it difficult to believe that Spinosaurus (which may have had some airsacks in only its neck at most, and could just as well have had none at all) would have a density around 8% lower than animals with very extensive airsacks in both their necks and torsos. -Most other theropods (which had significantly more airsacks than Spinosaurus did) do not seem to have been around the density of 0.833 either. For instance (although his conclusion on this blogpost was almost certainly incorrect for reasons I can explain if you so wish), Scott Hartman has come to a density figure of roughly 0.915 for Giganotosaurus when taking into account the (significantly greater) amount of airsacks in the head, neck, and torso. Molina-Pérez & Larramendi (2016) also support my viewpoint, suggesting an even higher figure of 0.95 (page 11) when taking into account the fact that all tissues save for fat are a good deal denser than water. Therefore I do not see justification for such a low density in Spinosaurus, given its dense bones and the much higher densities of even theropods that had many more airsacks. As stated above, I find a density of 1 or so the most plausible, and that would result in 3,864 kilograms for the new model of the neotype. '' The latest studies would say otherwise, for starters Symth et al provides evidence that they are the same animal, the unique autapomorphies are supposed to be a result individual variation (Sigilmassasaurus and S. Aegypticus) are not only the same genus but the same species, actually, even FSAC-KK-7280 is referred to Spinosaurus Aegypticus (not Sigilmassasaurus), the reason why its the most appropriate is quite simple and not the 3864kg is because the 1000 kg/m3 to gain a 3.8 tonne mass is by far too dense and heavy, adult organisms with air sacs don't magically loose them either with growth. In terms of presence/absence of air sacs, taphonomy cannot play into account like you suggest, because we have two separate individuals with the same pneumatised bone, it would be very coincidental that two separate specimens have pneumatised bone in the posterior cervical vertebra (exact same place!) it isn't even just Spinosaurus, it is a trait of other spinosaurids too. The high bone compactness occurs from the material obtained from the legs only, specifically compactness in the femoral shaft in contrast to the foramen in FSAC-KK-7280 and FSAC-KK-18122 is from the dorsal vertebra there is a difference in position. And the possibility of pneumatized bone density has directly came from Ibrahim et al 2020, ironically. Even Ibrahim et al Wasn't completely not pneumatic, it had a cancellous bone with pores, the femur specifically contains fibrolamellar bone that becomes increasingly cancellous towards the middle. Cancellous bone does have pores, so it's not completely solid bone like you claim by no air spaces in the 3800kg value. I find it suddenly weird how your more willing to agree with Ibrahim et al 2014 on a non-pneumatic Spinosaurus but willing to contradict Ibrahim et al 2020 which considers the possibility of a pneumatic Spinosaurus too. According to Lee et al 2014, Deinocherius rivalled the number of airsacs of sauropods, so other particular theropods could easily be exceptions to the general rule also Henderson 2003 actually has sauropod densities lower than the 833kg/m3 of Ibrahims pneumatic spinosaurus.(Apatosaurus's density 818 kg/m3, Diplodocus 814 kg/m3,Camarasaurus 791 kg/m3, Brachiosaurus 796 kg/m3) retrospectively...  *This image is copyright of its original author ''I think you may be interested to know that by superimposing the rostrum on a privately owned complete skull of Spinosaurus, SpinoInWonderland has achieved a skull length of 1.86 meters for MSNM v4047. My assumption is that his reconstruction should hold at least as much as any other if not moreso, since it is bases solely on the complete and undistorted skull of a conspecific, so I don't know whether you have anything that suggests this to be wrong, but 175 cm or more does not seem to be an overestimate to me and in fact seems quite probable. There's also the skull reconstruction of 177 cm by theropod1, which is to my knowledge still accurate.'' What you linked was a random image, that's not a source, MSNM V4047 is the largest specimen and even the max size of the skull is still smaller (175cm), SpinoInWonderland isn't a palaeontologist, nor is a image a reliable source and a link on how he got those measurements would be useful too. As explained MSMN V4047 is a overestimated because Sasso 2005 used different taxon to determine it's length, it is in fact overexaggerated, Hendrickx et al 2016, Therrien et al 2007, Ibrahim et al 2014 also agrees by favouring 1.5-1.6 metre long skull. ''Considering what I have outlined above, would you care to explain how 160 cm is an exaggeration? Also, for what it's worth, the 112 cm skull length figure for FSAC-KK 11888 would result in MSNM v4047 being about 17.1 meters long using the 10.93 meter estimate from Ibrahim et al. 2020 as well as theropod1's skull reconstruction for it. One last thing: Comparing Therrien and Henderson (2007) to the models from Ibrahim is not apples to apples. The formula of the former is based on a much more compact animal (a short tailed tyrannosaurid) as a general basis, and therefore using it as the basis for Spinosaurus length estimates is generally problematic. I find 16 meters (Henderson 2018, corrected model outlined earlier in this thread) to 17.1 meters more likely given that they base on actual conspecifics instead of an unrelated theropod with a completely different lifestyle, etc.'' 160cm is an exaggeration because (FSAC-KK 11888's skull is 112cm, basing this with a 32% increase for MSNM 4047 (Supplementary PDF for Ibrahim et al 2014) does not equate to 160cm but less than 160cm, (around 147cm) using Therriens length equation resolves much less than 17m around 12.5metres, isometrically scaling 32% from 11m (how they got 11 metres is unknown and dubious) neotype also gives a result of 14.5m at max, the scaling increase of FSAC-KK 11888's skull shows a good consistently with Therrien et al 2007's skull length. Henderson 2018 states nothing more than 15 metres in length by the way. ''Still too pneumatic if my above sources are anything to go by. The corrected model of this (page 7) is more than 12 tonnes.'' No absolutely not pre ibrahim 2020 spinosaurus was not 12 tonnes if it had no air sacs/pneumatised bone, how is it pneumatic at all if it's LACKING airspaces and PNEUMATIISED bone? ''As I have told you before, femoral circumference is not reliable to estimate mass: https://thesauropodomorphlair.wordpress....timations/'' If you actually read what I said, I mentioned why femoral circumfluence cannot be applied to Spinosaurus because of the unique marrow cavity affecting the accuracy of mass estimations (with Persons et al 2019 being referenced which your fully aware of challenging Campion et al's mass equations being applied to S. Aegypticus,and isometry is the only available option which I also quoted from Lakin et al 2019. Speaking of Mickey Mortimer's criticism, at same scale, Tyrannosaurus (skeletal from Hartman) and Spinosaurus (skeletal from Ibrahim) have almost identical proportional tail lengths.  *This image is copyright of its original author
Quote:The latest studies would say otherwise, for starters Symth et al provides evidence that they are the same animal, the unique autapomorphies are supposed to be a result individual variation Let's give you the benefit of the doubt here, then. Assuming Spinosaurus DID have a pneumatic neck, we need to take into account that it would have been denser than solely the pneumaticity suggests, as Molina-Pérez & Larramendi point out. As I have linked for the Google Books, they estimate the density of dinosaurs with far more air sacs than Spinosaurus would have had to have already had a density of 0.95, and that crocodilians (the relatively best model for non-maniraptorans, especially spinosaurids) have a density of 1.05 given their lack of airsacs, not simply 1 as one might expect, falling close to the disparity of what the theropod densities are when taking into account and not taking into account tissue density. And SpinoInWonderland's older Spinosaurus supports this well; with a density of 0.9 in the head and neck (as Scott Hartman used without taking into account the denser tissue) and crocodilian-like density in the rest of the animal, the density is overall 1.035. Not to mention, even extant birds (which are the theropods best known by far for being pneumatic) lose their pneumaticity and air sacs when they become semiaquatic. As Wedel et al. 2003 and Schorger et al. 1947 have noted, a very well known diving bird (the loon) has no postcranial pneumaticity at all, just to throw an example out there. And that makes sense, considering being as highly pneumatic is a very large hinder to a diving lifestyle as Spinosaurus is thought to have had. Therefore, based on absolutely EVERYTHING I outlined above, I find a density of at least 1 if not a bit more to be the most realistic by far. And where does Ibrahim (2020) suggest pneumaticity? I am not aware of this. Quote:According to Lee et al 2014, Deinocherius rivalled the number of airsacs of sauropods, so other particular theropods could easily be exceptions to the general rule also Henderson 2003 actually has sauropod densities lower than the 833kg/m3 of Ibrahims pneumatic spinosaurus.(Apatosaurus's density 818 kg/m3, Diplodocus 814 kg/m3,Camarasaurus 791 kg/m3, Brachiosaurus 796 kg/m3) retrospectively... Have you read what my Google Books link regarding sauropods stated? The old estimations for sauropod density are much too low because they do not take into account the much higher densities of relaxed animals, they often stem from the most popular publication on density (Wedel's) that overestimated the pneumaticity, and they did not take into account that all the tissues are much denser than water. Therefore I find a density of 0.9 to be more likely for sauropods that 0.791-0.814. And sauropods have significantly more pneumaticity than Spinosaurus, that is an objective fact. (And Deinocheirus would also go up somewhat in density, if it was similarly dense to sauropods it'd be 0.9 or so as they were). Quote:What you linked was a random image, that's not a source, MSNM V4047 is the largest specimen and even the max size of the skull is still smaller (175cm), SpinoInWonderland isn't a palaeontologist, nor is a image a reliable source and a link on how he got those measurements would be useful too. What SpinoInWonderland simply did was superimpose the rostrum (which is 98.8 cm long according to the Theropod Database), onto an image of a complete but privately owned Spinosaurus skull, and then given the rostrum length of 98.8 cm, the whole skull ended up at 1.86 meters. Is that really so hard to understand? Finally, just because he isn't a palaeontologist doesn't mean he can't do good work. As far as I can see he did the best he could due to the fact he used 100% conspecific material. Quote:As explained MSMN V4047 is a overestimated because Sasso 2005 used different taxon to determine it's length, it is in fact overexaggerated, Hendrickx et al 2016, Therrien et al 2007, Ibrahim et al 2014 also agrees by favouring 1.5-1.6 metre long skull. Your argument of using a different taxon goes completely down the drain considering that SpinoInWonderland used nothing except Spinosaurus skull material to get 1.86 meters. That's it. Also, using a different taxon does not necessarily make for an overestimate. Mind explaining just how and why theropod1's reconstruction for example may be overestimated? It uses different taxa but to his knowledge it still holds. Quote:160cm is an exaggeration because (FSAC-KK 11888's skull is 112cm, basing this with a 32% increase for MSNM 4047 (Supplementary PDF for Ibrahim et al 2014) does not equate to 160cm but less than 160cm, (around 147cm) using Therriens length equation resolves much less than 17m around 12.5metres, isometrically scaling 32% from 11m (how they got 11 metres is unknown and dubious) neotype also gives a result of 14.5m at max, the scaling increase of FSAC-KK 11888's skull shows a good consistently with Therrien et al 2007's skull length. Henderson 2018 states nothing more than 15 metres in length by the way. I'll ask this again. Can you explain how an equation based primarily on short tailed tyrannosaurids with no Spinosaurus material in its base sample size is superior to using actual Spinosaurus material? With the latter, that is how lengths of 16-17 meters or so are obtained. Also, Henderson (2018) states 16 meters as you can see here. Quote:No absolutely not pre ibrahim 2020 spinosaurus was not 12 tonnes if it had no air sacs/pneumatised bone, how is it pneumatic at all if it's LACKING airspaces and PNEUMATIISED bone? This isn't pneumatized? Looks like a density of 0.918 instead of 1 to me. Quote:This model has higher mean density of 918 gm/l Now sure, it has a higher density. But still very likely not high enough. Also, would you mind explaining just why the corrected version is so wrong considering I have put absolutely everything I could about it in line with current Spinosaurus knowledge and that is what led to such a high mass? Not to mention it matches the new model of the neotype at the same length almost perfectly, I see that as more confirmation that my corrections were on point. Quote:''As I have told you before, femoral circumference is not reliable to estimate mass: https://thesauropodomorphlair.wordpress....timations/'' My mistake. Point taken. Quote:Speaking of Mickey Mortimer's criticism, at same scale, Tyrannosaurus (skeletal from Hartman) and Spinosaurus (skeletal from Ibrahim) have almost identical proportional tail lengths. What does that have to do with this?
Let's give you the benefit of the doubt here, then. Assuming Spinosaurus DID have a pneumatic neck, we need to take into account that it would have been denser than solely the pneumaticity suggests, as Molina-Pérez & Larramendi point out. As I have linked for the Google Books, they estimate the density of dinosaurs with far more air sacs than Spinosaurus would have had to have already had a density of 0.95, and that crocodilians (the relatively best model for non-maniraptorans, especially spinosaurids) have a density of 1.05 given their lack of airsacs, not simply 1 as one might expect, falling close to the disparity of what the theropod densities are when taking into account and not taking into account tissue density. And SpinoInWonderland's older Spinosaurus supports this well; with a density of 0.9 in the head and neck (as Scott Hartman used without taking into account the denser tissue) and crocodilian-like density in the rest of the animal, the density is overall 1.035. Not to mention, even extant birds (which are the theropods best known by far for being pneumatic) lose their pneumaticity and air sacs when they become semiaquatic. As Wedel et al. 2003 and Schorger et al. 1947 have noted, a very well known diving bird (the loon) has no postcranial pneumaticity at all, just to throw an example out there. And that makes sense, considering being as highly pneumatic is a very large hinder to a diving lifestyle as Spinosaurus is thought to have had. Therefore, based on absolutely EVERYTHING I outlined above, I find a density of at least 1 if not a bit more to be the most realistic by far. And where does Ibrahim (2020) suggest pneumaticity? I am not aware of this.
Benefit of the doubt? It's pretty clear spinosaurus had a pneumatic cervical vertebra, and deep gaps at the back, from FSAC-KK-7280 and FSAC-KK-18122,theres direct evidence supporting it for it for crying out loud, how can spinosaurus have a SG of 1.0 if it had some sort of air spaces? 1000kg/m3 is based on no airspaces? Crocodllians/other specific theropods aren't good for example for spinosaurids because they simply have no air sacs at all, anything with air spaces the density is deceased of 1000kgm/m3, tissues vary in density too. Now with SpinoInWonderlands spinosaurus density, which is greatly overexaggerated (this is before Ibrahim et al 2020 incase you forget, MSMN V4047's mass is ten tonnes, imagine with the corrections how heavy it would be!) I got a density of 1 and not 0.9. Going by 1 litre = 1kg for FSAC KK11888 4443.13 litres = 4443.13 kg Volume in m3 (1 litre = 0.001 cubic metre (1000) 4.44313 cubic metres) Thats a speciffic gravity of 1.0 not 0.9? what are you talking about 0.9? Where are you getting that from? Density = mass/volume 4443.13/4.44313 = 1000 kgm3 Thats a speciffic gravity of 1.0 not 0.9? what are you talking about 0.9? I'm not sure where you got Hartman's density, and date of publication is essential too. Speaking of sauropods, I checked Henderson 2003 and it doesn't mention anything on the state of lungs when being calculated specific gravity if anything according to a blogpost, by open of the authors of the paper... Mathew Wedel, https://svpow.com/2009/03/16/brachiosaur...ncomplete/ states he calculated the density of Diplodocus too high he left out air spaces that were too difficult to calculate volume, the volume occupied by the lungs and air sacs, should have been doubled, so if what Larramendi is saying is true, this would compensate however I not fully read Wedel 2005 to double check. It should be taken into account that Henderson 2003 doesn't mention diplodocus anywhere, and calculates volume of 4 different sauropods which I've mentioned, even Larramendi guesstimates density around 0.9, not really support by no backing up for his claims either. That is not true, many semi aquatic birds still have hollow bones, terns, gannets, and pelicans, also are divers and have hollow bones, also little grebe a diving bird in the exact reference you gave about loons have a density of 0.86 despite having solid bones (but they do have air sacs), also it has been proved by Henderson et al 2018 that Spinosaurus was unsinkable, being to little dense to dive into water, also before you argue that it would roll, Ibrahim et al 2020 has addressed that argument, the tail fluke would decrease the potential ability to roll and stable the animal during locomotion. Also air sacs are an evolutionary advantage for regulatory and biomechanical needs for which a large spinosaurus would benefit. They don't suggest pneumaticity but they consider it an option for FSAC KK11888's density and mass ''What SpinoInWonderland simply did was superimpose the rostrum (which is 98.8 cm long according to the Theropod Database), onto an image of a complete but privately owned Spinosaurus skull, and then given the rostrum length of 98.8 cm, the whole skull ended up at 1.86 meters. Is that really so hard to understand? Finally, just because he isn't a palaeontologist doesn't mean he can't do good work. As far as I can see he did the best he could due to the fact he used 100% conspecific material.'' See this is where I'm starting to get the impression you are cherrypicking, why make it overcomplicated than it should be, just simply apply isometry, a 32% of a 112cm FSAC-KK 11888's skull to get MSMN v4047's skull length of 150metres which is bang on what Therrien and Henderson got, as well as Ibrahim and colleagues.These are multiple experts saying the same thing in multiple papers and not a single image from not even an qualified expert, just like what you said about trusting Ibrahim supposed opinions over evidence, you are changing it by then contradicting Ibrahim himself on another point. No the thing is you are not supporting any of your claims with reliable evidence, don't forget palaeontology is a science, you've barely supported your claims with any scientific literature (studies, especially done by the peer review process) all you've done is mainly took SpinoInWonderlands blogs and opnions as well as poor sources like images for example for gospel you can't just link someone whos not a palaeontologist, you can get references from him who have been done by qualified experts in their fields but that's mainly it you have to have a origin of your references. ''Your argument of using a different taxon goes completely down the drain considering that SpinoInWonderland used nothing except Spinosaurus skull material to get 1.86 meters. That's it. Also, using a different taxon does not necessarily make for an overestimate. Mind explaining just how and why theropod1's reconstruction for example may be overestimated? It uses different taxa but to his knowledge it still holds.'' So did Ibrahim and Therrien, The morphology of skulls on spinosaurid is drastic, theres too much variation upon spinosaurids, especially posteriorly to get an accurate size, isometrically smaller relatives of a given genus to obtain body length is unreliable because those smaller theropods do not have proportional skull to body length sizes infact scaling actual spinosaurus material ,FSAC KK11888,should be the most reasonable and gives 150cm. ''I'll ask this again. Can you explain how an equation based primarily on short tailed tyrannosaurids with no Spinosaurus material in its base sample size is superior to using actual Spinosaurus material? With the latter, that is how lengths of 16-17 meters or so are obtained. Also, Henderson (2018) states 16 meters as you can see here.'' I just did at the bottom, I don't know where you got the idea that Therrien et al 2007 specifies in short tailed tyrannosaurids? Really tyrannosaurids? there's only two that was in the paper at all.How do you know that even either with certainty? The digital model itself was 15.5 (based on Ibrahim et al 2014) metres which was rounded to 16 ''What does that have to do with this?'' That skeletal diagram was to show why Mickeys short tailed argument is invalid, simply because they have similar tail lengths are similar size, don't forget unusual theropod body plans like ornithomimosaurs and oviraptosaurs were discredited ''Now sure, it has a higher density. But still very likely not high enough. Also, would you mind explaining just why the corrected version is so wrong considering I have put absolutely everything I could about it in line with current Spinosaurus knowledge and that is what led to such a high mass? Not to mention it matches the new model of the neotype at the same length almost perfectly, I see that as more confirmation that my corrections were on point.'' Based on what, even if what your saying is true, 918 kg/m3 is higher than the minimum you said is for spinosaurus which according to you is 0.9, also the limbs of Hendersons spinosaurus was 1.05 SG I checked page 7, barely anything could be taken with consideration barely any sources at all. Quote:Benefit of the doubt? It's pretty clear spinosaurus had a pneumatic cervical vertebra, and deep gaps at the back, from FSAC-KK-7280 and FSAC-KK-18122,theres direct evidence supporting it for it for crying out loud, how can spinosaurus have a SG of 1.0 if it had some sort of air spaces? Those vertebrae MAY belong to Spinosaurus but that is not 100% certain. I gave you the benefit of the doubt in assuming it did. Also, have you considered that a density of 1 or more is still possible, even with airsacs, because most tissues as a whole are denser than water? Quote:1000kg/m3 is based on no airspaces? Crocodllians/other specific theropods aren't good for example for spinosaurids because they simply have no air sacs at all, anything with air spaces the density is deceased of 1000kgm/m3, tissues vary in density too. Crocodilians naturally have a density of 1.05 kg/l following Asier Larramendi's works. What I actually did was give the head and neck of SpinoInWonderland's Spinosaurus a density of 0.9 and the rest a crocodilian density to show that even with airsacs an animal can be as dense or denser than water. Quote:Now with SpinoInWonderlands spinosaurus density, which is greatly overexaggerated (this is before Ibrahim et al 2020 incase you forget, MSMN V4047's mass is ten tonnes, imagine with the corrections how heavy it would be!) I got a density of 1 and not 0.9. Read what I wrote above. The head and neck were given 0.9, and the rest 1.05, which ended up in an animal with a density of 1.035. Quote:Going by 1 litre = 1kg for FSAC KK11888 I got it from Scott Hartman's blogpost, which has been clearly linked in my first reply to you. But if we're going to reference the date of publication, Asier Larramendi's work is more recent (2016), and suggests a density of 0.95 for the majority of theropods. This density has been used on significantly more pneumatic animals than Spinosaurus (eg: Aerosteon), and therefore I find it hard to believe a much less pneumatic theropod would have been as pneumatic or less than many theropods with a lot more airsacs. Quote:Speaking of sauropods, I checked Henderson 2003 and it doesn't mention anything on the state of lungs when being calculated specific gravity if anything according to a blogpost, by open of the authors of the paper... Mathew Wedel, https://svpow.com/2009/03/16/brachiosaur...ncomplete/ states he calculated the density of Diplodocus too high he left out air spaces that were too difficult to calculate volume, the volume occupied by the lungs and air sacs, should have been doubled, so if what Larramendi is saying is true, this would compensate however I not fully read Wedel 2005 to double check. That paper got their densities from dead birds that had lungs inflated to the very maximum (a far cry from live, relaxed sauropods with considerably less inflation in theirs), and it failed to take into account that the tissues were denser than water. Also, it should be noted that Wedel has overestimated the airspaces if we follow Larramendi, let me get a screenshot.  *This image is copyright of its original author Larramendi seems to have covered everything on sauropod density that I can think of, and I don't see much reason at this point to doubt a density of roughly 0.9 for sauropods. And therefore, since sauropods are MUCH more pneumatic than Spinosaurus but still have a density of 0.9, I strongly believe Spinosaurus would be a good deal denser than what you suggest. Quote:That is not true, many semi aquatic birds still have hollow bones, terns, gannets, and pelicans, also are divers and have hollow bones, also little grebe a diving bird in the exact reference you gave about loons have a density of 0.86 despite having solid bones (but they do have air sacs), also it has been proved by Henderson et al 2018 that Spinosaurus was unsinkable, being to little dense to dive into water, also before you argue that it would roll, Ibrahim et al 2020 has addressed that argument, the tail fluke would decrease the potential ability to roll and stable the animal during locomotion. There exists a difference between what you and I are using as a reference. Loons do not seem to fly as much as terns, gannets, pelicans, and grebes, and they also seem to spend more time in the water and dive deeper, so it is therefore presumable they are less pneumatic because of it. And I didn't say any airsacs at all would be detrimental, what I am saying is that an animal of 0.833 kg/l is far less realistic that 1+ kg/l given everything above. Finally, keep in mind that simply having airsacs does not prevent a density of 1 or more as shown above. Quote:See this is where I'm starting to get the impression you are cherrypicking, why make it overcomplicated than it should be, just simply apply isometry, a 32% of a 112cm FSAC-KK 11888's skull to get MSMN v4047's skull length of 150metres which is bang on what Therrien and Henderson got, as well as Ibrahim and colleagues. Or it could simply mean the size difference between those specimens is more than 32%. That would also be supported by the size of the corrected model from Henderson (2018) and some other skull reconstructions. Quote:These are multiple experts saying the same thing in multiple papers and not a single image from not even an qualified expert, It doesn't matter if it's peer reviewed or not, what does matter is if it's factually correct. And you have given no evidence suggesting it not to be other than fallaciously suggesting inaccuracy due to no peer reviewing. And show me where I'm taking anything as gospel here? I am aware nothing is truly gospel in palaeontology, so I'm simply endorsing what I find most probable. Quote:So did Ibrahim and Therrien, The morphology of skulls on spinosaurid is drastic, theres too much variation upon spinosaurids, especially posteriorly to get an accurate size, isometrically smaller relatives of a given genus to obtain body length is unreliable because those smaller theropods do not have proportional skull to body length sizes infact scaling actual spinosaurus material ,FSAC KK11888,should be the most reasonable and gives 150cm. Then would you mind explaining exactly why the larger estimates of theropod1 and SpinoInWonderland (especially that of SpinoInWonderland to which your argument of using a different species doesn't apply) are wrong? What you seem to be saying is that they are wrong because they are large, and you don't give any explanation for exactly why the skull reconstructions of either have been done wrongly. Quote:I just did at the bottom Sorry, I'm afraid I can't see this explanation, whatever it was. Would you mind repeating it? Quote:I don't know where you got the idea that Therrien et al 2007 specifies in short tailed tyrannosaurids? Really tyrannosaurids? there's only two that was in the paper at all.How do you know that even either with certainty? In their sample size for the equation, they used Greg Paul's tyrannosaurid skeletals from Predatory Dinosaurs of the World, which happened to have rather short tails. Quote:The digital model itself was 15.5 (based on Ibrahim et al 2014) metres which was rounded to 16 Can I see a source for this? Quote:That skeletal diagram was to show why Mickeys short tailed argument is invalid, simply because they have similar tail lengths are similar size, don't forget unusual theropod body plans like ornithomimosaurs and oviraptosaurs were discredited I don't recall referencing Mortimer's arguments here, therefore I do not see the point of that. Quote:Based on what, even if what your saying is true, 918 kg/m3 is higher than the minimum you said is for spinosaurus which according to you is 0.9, also the limbs of Hendersons spinosaurus was 1.05 SG The minimum density of the neck was 0.9, my estimation of density for the whole animal was 1.034. And despite the dense limbs, Henderson's model is still very likely too pneumatic for all the above reasons. Quote:I checked page 7, barely anything could be taken with consideration barely any sources at all. What on Earth are you talking about? I gave all my sources and methods right there in the post! If there is anything that you need clarification on, just ask. Edit: As it turns out, the skull length on the newest skeletal of the neotype from Ibrahim et al. 2020 is 122 cm, not 112 cm. Based on that and SpinoInWonderland's 186 cm estimate for MSNM v4047's skull length, MSNM v4047 would have been 16.63 meters long and 13.7 tonnes. theropod1's skull length estimate of 177 cm also yields a very large size - 15.86 meters and 11.8 tonnes. The mean of these 2 estimates is basically the same as the corrected model from Henderson (2018), so I'd consider these further support still for very large sizes.
I made an response, but my messages arent being approved, I've sent it twice now,
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