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Spinosaurus News ~
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 Quote:The thing is, if you like it or not, they have been assigned to Spinosaurus, it's not a may, its confirmed for now, fsac kk 18118 sigilmassasaurus unlike fsca kk 720 Nowhere did I say that those were not assigned to Spinosaurus. What I said was that the assignment is not 100% certain. Quote:Tissues vary with density, animals with the presence of air sacs (birds) have a density less than 1.0. Not necessarily, I have shown how it's possible for that not to be the case. And tissues do vary in density, but because muscle and blood (1.06 kg/l) as well as bone (2+ kg/l) and probably many more are denser than water, that would mean that a density of 1 or more is still possible even when there are airsacs. I don't know how many times I explained this already. Quote:See the thing is you never really specified this in the first place, you just magically applied a 0.9 density for SpinoInWonderLand's spinosaurus, which the actual image itself contradicts, also finding total density I would still think the total density is less than 1.0, (1.05+0.9 then /2) I believe Donald Henderson and Young nailed density correctly with a pneumatic neck,heads and body (based on other theropods) while having the limbs have a specific gravity of 1.05. I did specify that, maybe you just didn't read my post close enough. But give it a try yourself; the total volume of the head and neck is 1073.69 litres, while the rest of the animal is 9595.86 litres. If you multiply the head and neck by 0.9, and the rest by 1.05, I am not aware of any way to get an overall density of 0.9. Quote:I've already discussed the sauropod argument of yours I see. I'll discuss that with you further down the post. Quote:Hartman doesn't specify how he got these densities I'm not Hartman but he could have got them from Bates et al. 2009 (come to think of it, his densities are probably a bit conservative based on the work of both Bates and Larramendi). Quote:also the thing you quoted was in reference to SpinoInWonderlands image I'm a little bit lost on this. In my last post to you, the response paragraph that simultaneously dealt with Hartman's densities and what kind of density Aerosteon was likely to have had did not reference SpinoInWonderland's work. Quote:I checked Sereno et al 2008, and I'm not aware of a density value of Aeroteon. Sereno was not looking for a density for Aerosteon. Molina-Pérez and Larramendi were, however, and on every theropod in their book a graphic double integration was used with the 0.95 density. And I therefore will need evidence that a megaraptoran tyrannosauroid that's so pneumatic it was named for the air in its bones is going to have a higher density than an aquatic spinosaurid megalosauroid which could plausibly have been denser than 1 based on modern relatives. Quote:I checked Wedel 2005, maybe you can too, I haven't seen any quote from their methods that they used dead birds, and why did you not take into my blog post from Wedel himself the author of the paper saying if anything he UNDERestimated sauropod density https://svpow.com/2009/03/16/brachiosaur...ncomplete/ This is a clear contradiction to what you are saying, theres no direct density value for tissues they vary, Wedel literally left out air spaces and halved the air volume from the lungs, I also showed you Henderson 2003 which have densities not even from Diplodocus that have much lower total densities than 0.9. This abstract from Wedel's paper suggests otherwise; it seems as though dead and inflated birds were used as reference. Quote:Data presented by King (1966:table 3) indicate that the lungs and air sacs of birds may occupy 10%–20% of the volume of the body. Hazlehurst and Rayner (1992) found an average SG of 0.73 in a sample of 25 birds from 12 unspecified species. On this basis, they concluded that the lungs and air sacs occupy about a quarter of the volume of the body in birds. However, some of the air in their birds probably resided in extraskeletal diverticula or pneumatic bones, so the volume of the lungs and air sacs may have been somewhat lower. In the interests of erring conservatively, I put the volume of the lungs and air sacs at 10% of the body volume. Also, the things Wedel did not take into account were that the density of normal, relaxed sauropods is much higher as well as tissues being denser than water to begin with. Furthermore, Larramendi has outlined how the air spaces were overestimated in the original density of 0.8, and not even birds are that pneumatic when relaxed. Not to be blunt but you haven't been refuting Larramendi's proposition at all; you're just ragging about old stuff that his density estimation took into account. One last thing. I've spoken with Wedel in SVPOW's comments, and he thinks 0.9 is viable these days. So in conclusion, for Spinosaurus to have been significantly less dense than sauropods really does not seem viable from known data. Quote:Ummm, loons have known to fly 500 miles in a 24 hour period, they are just as aquatic as Grebes, and yes animals with air sacs have a density less than one, even with solid bones like loons. Are they really? Loons appear to spend more time in and around water and less time in the air going by what I could find. And nowhere did I say they couldn't fly, I said they did not seem to fly as much and were solid boned with a high density due to that. Quote:Henderson got 15 metres from Ibrahim et al 2014, which in return favours 14.5 metres, which is dubious because of FSAC-KK 11888's length was not detailed on how it was 11 metres. I'll go over Henderson further down, but I don't see why a discrepancy of more than 32% is dubious or incorrect. With the newest model and with the skulls restored using the same criteria, I am not able to replicate a mere 32%. Also, they simply restored the skeleton and got 11 meters or so. That's all that was done. Quote:How do you define factually correct? Exactly how it sounds, facts that are correct. Which can be just as viable non-peer-reviewed as they are peer-reviewed as long as they are correct. (An example of this would be saying that Spinosaurus was a reptile. That's just as correct coming from a non peer-reviewed source as it is from a peer reviewed one because it is factually correct that dinosaurs are reptiles and therefore peer review does not matter in that case). Quote:In this debate you provided barely anything thats peer reviewed That does not matter. What matters is how factually correct it is, and like I said before you don't seem to have any refutations save for the fallacy of no peer reviewing. Quote:I am not saying everything has to be, but the majority of your sources are poor resolution images or from people who aren't even experts, why don't you at least borrow the sources from those people which are in return peer reviewed? You see when something has been approved by two qualified experts, then it has much more reliablity. Why don't you actually take some time to point out why you think my images are wrong instead of constantly just ragging about no peer review as you are doing now? I don't need peer reviewed material for the above reasons, but what you need to do is actually point out why you think it is wrong. Quote:Also could you mind not stating false statements, I don't see what is so false about this. With both skulls restored using the same criteria, I just could not replicate a 32 percent size difference, and I don't know what Ibrahim did to get 32%. Simple as that. Quote:I have specifically stated much more reasons, the 32% skull difference between FSAC-KK 11888 and MSMN v4047's skull length, as well as Henderson and Therriens separate downgrade. Then the onus is on you to show how a difference of 32% can be obtained when both skulls are restored using the same criteria. I cannot replicate 32% as I can 52.5% and I don't know how Ibrahim got it, like I have said before. Quote:You seem to reference SpinoInWonderLand way too much than you should Nothing wrong with referencing him as much as I do, he is a good source so far as I can see. Quote:which is almost like taking his word for complete gospel Mind explaining how? It's simply what I find most probable, I think you know as well as I do that I am taking nothing for gospel here. Quote:we are all aware palaeontology is a ever changing field with newer discoveries That is the very reason I don't take anything as even close to gospel. I even stated this in my other post. Quote:Also it doesn't scientifically matter whats ''factual'' or not, this is science, science has to go through a process of being factual in the first place, anything that hasn't gone through the requirements is like it or not is invalid. Then please explain exactly what makes my non peer-reviewed arguments factually incorrect. Quote:Because SpinoInWonderlands imagery placing is simply too simplistic (as if it was that simple!) aren't these skull reconstructions anyway? I'm failing to see how being simplistic makes it wrong. The reason it was so simple is that all that needed to be done was superimpose the rostrum on a complete and undistorted Spinosaurus skull. That's it. And I find his skull reconstruction the most probable (but nowhere near gospel contrary to what you may think) given that it uses only Spinosaurus material. Just like I said before. Quote:Theropod1's I have already explained because he/she like you claim used seperate spinosaurid taxon That doesn't necessarily make for a wrong reconstruction. Can you please explain what turned out so wrong when the different taxa were used to fill in the gaps? Quote:I am not saying that at all, if anyone you seem to be maximising the size of it, I am simply endorsing what I find to be the most realistic based on known data. Quote:it is normal for prehistoric fauna to downgrade in size It is also common for them to upgrade in size. And based on known data, I find the latter most probable. Quote:You see I have checked Therrien et al and tried to quickly see if him and Henderson used Paul's 1988's skeletals, also I scaled Ibrahim et al 2020's spinosaurus and Pauls Tyrannosaurus, and its actually the opposite even with a curved tail it is longer That doesn't change the fact that the results from Therrien and Henderson (2007) end up too short compared to what 100% Spinosaurus material would yield, because for a given mass Tyrannosaurus is shorter than Spinosaurus. And that was my point, that that formula overestimates the weight but seems to underestimate the length. Quote:It's literally from Henderson et al 2018 That sounds like they are talking about the Ibrahim et al. 2014 model rather than the model that was used in the study. And given that nothing else was rounded off in the data table, I find it most likely that the 16 meter estimation refers to a non rounded measurement of the study's own model. Quote:You just been using his arguments from the beginning http://dml.cmnh.org/2007Mar/msg00292.html It's purely coincidental in that case, because I had not seen that entry of the DML until you linked it. But I will say that Mortimer does make good points there. Quote:Not really, barely any sources at all just poor resolution images. Everything had been explained in those posts. Including what changes had been made to the model, why those changes were made, and how they were made. I really do not see how that is no sources at all and just poor resolution images. Quote:I am not here to dissect you, I am here to post another side to the argument on my findings so a view could determine for his/her self And I am here to defend my viewpoints. Quote:The head NOT the skull, where does it say skull? Those can be used interchangeably when referring to things like dinosaur skeletals. Quote:Also this still gives a length of 160cm, As I said, I cannot replicate such a relatively low size difference between the 2 specimens. Quote:I have gave my own mass estimates for 160cm (around close to 7 tonnes). A 160 cm skull, even though it seems to be a serious underestimate for all the above reasons, would yield more than 8.7 tonnes. Now DrZap, I say this with all due respect, but I think it's time that you and I drop the debate with one another. We've had this debate multiple times already, it's been going on for quite a while, and we have been beating around the bush a lot. I also don't know if I'll change your viewpoints regardless of whether more people believe you or me. Whether you reply to this post or not, I don't think I will be continuing to debate. Anyone else who would like to know more can feel free to ask me about anything (including what DrZap says should they reply to this post), but I'd like to respectfully drop the debate with DrZap specifically for the reasons above. Edit: Seems DrZap has now replied to this post. I'm now up for questioning if anyone has any questions about their reply to me. |
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