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Tyrannosaurus rex
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Ah, here we go! Hopefully this will not be deleted. Removed all the giant images for the sake of shortening the post.
@GuateGojira Quote:The bait: I'm sorry, I don't see at all how that's the case. I'm simply stating my opinions on the matter of these theropods' sizes just as anyone who uses this site can. If you don't like my formatting I'll bear that in mind and can use a different format, but I don't see how stating my disagreement makes me a 'fanatic'. It just makes me someone who disagrees. Quote:The analysis: I don't see at all how simply being of the opinion that Tyrannosaurus wasn't the largest theropod gives me a grudge against it or means I constantly downgrade it in my size calculation posts. I have my reasons behind my posts for size estimations which are easy to see in any of my posts, and they just so happen to make some theropods bigger than Tyrannosaurus. I'm not attempting to downgrade Tyrannosaurus whatsoever; these size estimates end up as they are and they tend to be very different from popular estimations with anatomical inaccuracies because in those posts I just so happen to fix those inaccuracies (such as fixing the mismounted ribs, extra fat, and lack of spinal curvature in a Sue model, or correcting the common problem of an incomplete pectoral girdle in Giganotosaurus). And if those posts just so happen to give large carcharodontosaurids a weight advantage over Tyrannosaurus, so be it. Just because they do does NOT mean they are wrong. What you're basically saying is that I'm downgrading Tyrannosaurus by fixing a mismounted model while inflating carcharodontosaurids by fixing the problem of the pectoral girdle. Would you care to explain how that is inflating/downgrading instead of just fixing anatomical problems and getting different size results? Furthermore, the reason why I give no links to what SpinoInWonderland tells me is because it's personal communication, NOT because others disagree with it. As you know, it's impossible to link personal communication. If you so wish however, I can provide a number of disagreement-free screenshots to where he has told these things to me. Last but not least, as for my data having no base except SpinoInWonderland, that's not true whatsoever and the opposite is easily visible to anyone who objectively reads my size estimation posts. While I do rely on SpinoInWonderland for a number of things, I also reference other experts, including Nizar Ibrahim, Donald Henderson, GetAwayTrike, and Greg Paul. Would you also care to explain how the results I got are so baseless especially considering they fixed the anatomical inaccuracies that the low estimations for carcharodontosaurids and Spinosaurus as well as the very high estimations for Tyrannosaurus had, and that I went over that in those very posts? Quote:I see that you complain about the comparison of the oldest T. rex with the specimens of Giganotosaurus and Carcharodontosaurus known, however the use of an "average sized" T. rex is also completelly incorrext, as we don't know if they were fully grow or if they will grow more with time (which seems to be the case), also we don't know the sexes of the animals so you are mixing females with males, we don't know if there could be also different subspecies (as those specimens are from diferent areas and some of them had a couple of thousands of years of difference (and we know what a few thousands of years can make to an species/subspecies). So your aproaching is incorrect and that is why we use the best that each species can offer. We don't know if those specimens of Carcharodontosaurids are young or old, there is simple no point of comparison and even compare between them is at some point futile as these are completelly diferent animals with different morphology (is like compare cats with dogs). All the specimens included in my sample ARE adults, following Mickey Mortimer at the Theropod Database as well as the histological studies (eg: Erickson et al. 2004, Horner and Padian 2004) suggest. As for differentiating between morphs, genders, etc, that's not possible at this time for obvious reasons. And about not knowing how old the carcharodontosaurids were, that's exactly my point! We don't know how old they were, but we can infer via parsimony that they were almost certainly not senescent as Sue and Scotty were, and due to the lack of studies we don't even know if they are fully grown! So if anything this favors the carcharodontosaurids unless every single individual of Giganotosaurus, Mapusaurus, Carcharodontosaurus, etc ever found turn out to be old and senescent adults. Quote:By they way IF you try to use the document of Therrien and Henderson (2007) you must remember that those results are already labeled as invalid by any expert at this moment. Please show me where I use or reference Therrien and Henderson (2007) in any of my posts as a basis for size estimations. I am well aware of the problems with that paper and therefore I do not use it whatsoever. Quote:However I was checking the available litterature and I could not found any formal document of any expert stating a calculated body mass of any theropod that surpass the T. rex in modern years, specially after the refining of the methods. In fact, some of the same experts that calculated the huge weights for Giganotosaurus and Spinosaurus already retracted and now recognize that T. rex is heavier than both. When I checked your "sources" all what we have are, again, the posts of Spinoinwonderland, so I ask, are you actually investigating or are you just using the preconcived ideas of this person? What experts say is only relevant if it's based on a rigorous model with no anatomical problems for instance. Even then, Greg Paul (2016) has a number of theropods (Giganotosaurus and Spinosaurus for instance) as larger than Tyrannosaurus based on volumetric rigorous models, and his Giganotosaurus is underestimated as-is, as I will go over below. But even still, I consider my size estimations to be the best so far that are available to me given the rigorous work I put into them. As for Spinosaurus and Giganotosaurus being supposedly lighter, that is based on the old Spinosaurus estimations before the new study (which still outsized the average Tyrannosaurus), and the Giganotosaurus is based on taking the incomplete scapula as complete, which lead to a major underestimation due to the very shallow chest. I'll go over this further down the post. Lastly, about my sources, I am indeed investigating quite a lot and this is easily visible to anyone who reads them objectively. I am NOT just using preconceived estimations from SpinoInWonderland; if you take a look at any post you'll see I go through a number of steps to get the final result. I don't see how this is solely preconceived ideas whatsoever; you're going to have to show me why my size estimation posts are like that if you think that's the case. Quote:I had not found any official weight estimation for Carcharodontosaurus, but the biggest specimen SGM-Din 1 is form only by an incomplete skull, that by the way was incorrectly reconstructed based in Gregory S. Paul and Scott Hartman. There are several reconstructions in the web, but certainly the best one is that of Franois with used the holotype and also other relatives to make one of the most reliable reconstructions. Would you care to explain why Franoys' is 'certainly the best', considering that I have outlined numerous plausible ways to get SGM-DIN 1 to 9-9.8 tonnes, one of which directly involves Franoys' skeletal itself? And you can't just say that SGM-DIN 1 was factually smaller than MUCPv-Ch1, considering not only do we not know that for certain but considering that as stated above, there exist numerous very plausible estimations that suggest a much, much bigger animal. One last thing: You don't need a 'Pinocchio nose' to get a >1.6 meter SGM-DIN 1 or these estimations I am referring to. Check SpinoInWonderland's 161 cm skull restoration or Theropod1's 163 cm skull restoration; these have no extra elongation whatsoever. Quote:Then it comes the Giganotosaurus, all the new studies recognize that T. rex was more robust and the idea that the specimen MUCPv-95 could be only an specimen with a more robust mandible (like T. rex "Stan" compared to other specimens). This is a good conclution from Hartman: https://www.skeletaldrawing.com/home/mas...edux772013 Just because Tyrannosaurus was more robust does NOT make it larger on the spot. (This is a response to both your other post and @Spalea's post with both of them addressing me on robusticity. Would either of you care to explain how Tyrannosaurus being more robust makes it larger? It simply makes Tyrannosaurus more robust regardless of how it compares sizewise with other theropods. Graphic double integrations and volumetric models do not lie, and these very plausibly result in several less robust theropods outmassing Tyrannosaurus as I have outlined in my post. If these models are wrong simply because of that, please explain why). Also, for MUCPv-95, who's to say it didn't belong to an animal that was MORE than 8 percent larger than the holotype but with a proportionally smaller head and jaw? Error bars go both ways you know; MUCPv-95 could be 10% larger for all we know. Isometry is our most parsimonious assumption since it requires less extra assumptions, and the most parsimonious assumption gives 10.29 tonnes for MUCPv-95 based on correcting the pectoral girdle and going by Greg Paul's skeletal. Scott Hartman's estimates for Giganotosaurus there are major underestimates because the skeletal takes the incomplete scapula as complete and therefore the chest is much shallower than it would have been. By the way, I have spoken with Scott Hartman about this and he seems to agree the estimations are better than his original ones where the incomplete scapula problem existed. I can screenshot where he said so if you'd like. Quote:Now, about the biggest Giga specimens, he says that "I must reiterate, the lower jaw fragment of MUCPv-95 does not come from an animal that is 8% larger than the type. In fact it honestly could be from an identically-sized animal that just has a more robust dentary, so scaling it up 6.5% (in linear dimensions) should if anything be seen as the upper bounds." So probably that jaw fragment belonged to a similar sized animal only that had a more robust mandible. This is completelly plausible as with such a low sample we don't know the variations that existed in this species. Again, we work with what we have. Once again, you're ignoring the fact that the error bars go both ways and that this could very well be an animal more than 8% larger with a proportionally smaller head and jaw. The isometry is our best bet as stated above, and this gives around 9.49 tonnes (SpinoInWonderland's GDI's of both GetAwayTrike's skeletal as well as his own) to 10.29 tonnes (Greg Paul skeletal with scapula corrected). Quote:Check this other reconstructions: There's nothing that says Giganotosaurus HAS to be smaller than Tyrannosaurus; in fact, as stated above, the corrected data suggests quite the opposite as previously stated. And yet again, I don't see how Scott Hartman's skeletal that has the chest very shallow is as accurate as Paul's and GAT's skeletals with that corrected; if you only consider it more accurate because it leads to a lower body mass then that is blatantly incorrect. Also, if anything, that Vitamin Imagination comparison has the Tyrannosaurus substantially overestimated and Giganotosaurus substantially underestimated. The Tyrannosaurus is very overestimated because it's based on the mount's mismounted ribcage, while the Giganotosaurus is very very underestimated due to the pectoral girdle issue I have went over well enough above. Finally, please explain to me how 13 meters for Carcharodontosaurus is an overestimation especially considering I have outlined numerous plausible estimations for it to be that large. Quote:Finally with Mapusaurus, you are using only one small fragment of a pubis to make wild estimations of sizes, the specimen MCF-PVPH-108.145. There is no evidence that the particular specimens belonged to a giant, probably it was just a robust specimen, and in this case there are several specimens to compare. Check this reconstruction: The most parsimonious assumption is that it belonged to an animal 110% the size of the Giganotosaurus holotype because that is what the pubis seems to indicate and it requires the least extra assumptions. MCF-PVPH-108.145 could be an animal with just a big pubis, but it could also be an EVEN LARGER animal with a smaller pubis; you're ignoring the error bars going both ways. And even if we disregard that, we still have the tibiae that lead to >9.7 tonne specimens for Mapusaurus, and the specimen was almost certainly this large because at these sizes for theropods, tibiae are almost always isometric. Quote:Apart from the estimation of Franoys, all the other estimations that I found shows that this animal was no more than 5 metric tones. Care to explain how a carcharodontosaurid with many specimens larger than the 8.17 tonne MUCPv-Ch1 could only be 5 metric tons? Quote:So, none of the Carcharodontosaurids, using reliable reconstructions and based in published papers, present specimens of the same body mass than T. rex. So, while thise giant predators were as long as T. rex, they were lighter in body build with specimens of up to 7 tons, and maybe the largest Giganotosaurus at 8 tons, IF it was actually larger than the holotype. Once again, I would like some explanations for why my estimations that put numerous carcharodontosaurids above Tyrannosaurus sizewise aren't accurate, especially considering they fix the very problems that the lower estimates had and fixing those things led to higher estimations. Quote:Finally we reach Spinosaurus, wich is the most probelmatic of all. This animal has no relation or any resemblance to any of the previous carnivore dinosaurs, so estimating its body size is difficult. At this moment we know that the best estimation is that this animal measured up to 15 meters long and weighed about 6.4 - 7.5 metric tons (Molina-Pérez & Larramendi 2016; Henderson, 2018) and this is the figure quoted by National Geographic, which expended a lot of time and money to make this animal famous, so there is no reason to think that they are going to downgrade this animal. Those estimations were made WELL before the new paper and new model so it's not surprising that they are smaller than 10-12+ tonnes. By the way, if you don't remember, correcting the model from Henderson (2018) leads to an animal over 12 tonnes, so would you care to explain how the 7 tonne estimation is more accurate than the >12 tonne estimation that fixed all the problems the 7 tonne estimation had? Also, as I have told you before, the new article made no reference whatsoever to the new volumetric model most likely because it was easiest to stick 7 tonnes in which was the estimation everyone already knew. Quote:Now, even with the new form, that sale in the tale will not represent more than 500 kg, so in the best case Spinosaurus probably weighed about 8 tons, which is about the same as the biggest Giganotosaurus and still lower than T. rex. We know that Ibrahim made a personal estimation of about 10 tons, but until there is a published paper about this, his figure is only his persona opinion and may change in a ny moment. I see no reason to trust the low estimations over the double digit tonnage considering that not only does Ibrahim CURRENTLY support that figure, the new model conforms to it and correcting some old models (like Henderson 2018) also falls in line with it. I've gone over this with you numerous times and you still have given no reason not to trust the corrected 10-12+ tonne estimates other than them seemingly being too high for your liking. Quote:By the way, I still don't see any explanation about WHY Spinoinwonderland reconstructed in a completelly different form the tail of Spinosaurus: The way he restored the tail is not incorrect whatsoever. Take a look at this blogpost: https://thesauropodomorphlair.wordpress....-taletail/ Quote:GetAwayTrike made it much better, even when its sale is weird: Reason? The spines of Spinosaurus are distorted and broken so there will be an error margin to restoring them. Quote:At the end, even if Spinosaurus reached the 9 tons of T. rex, The 9 tonne estimations for Tyrannosaurus are almost certainly incorrect, I have explained this in my post correcting the model from Hutchinson (2011) and can explain further if you wish. Quote:is that actually relevant? As @Spalea said, this dinosaur was an AQUATIC animal, the taphonomic evidence suggest that this animals largely aquatic and that spend much of its life in the water, not in land (Beevor et al., 2020), its jaw articulation was convergently present in pterosaurs and particularly pelecanids, were able to swallow large prey such as fish in the same way as pelecanids, supporting its prey selection (Hendrickx et la., 2016) and while is often been described as “crocodile-mimic” there is a suite of craniodental characters shared by spinosaurs and pike conger eels and may result from similar feeding behaviours. This typical jaw morphology likely represents an effective biomechanical adaptation for biting and grabbing elusive prey items in low-light aquatic environments (Vullo et al, 2016). This evidence suggest that Spinosaurus lived int he water, eated in the water and hunted fishes. So any idea that this animal was at land fighting Carcharodontosaurus is just child dream of its fans! I don't care for Tyrannosaurus vs Spinosaurus, but I see no reason why Spinosaurus should be excluded from giant theropod discussions. It's still a giant theropod, just an aquatic one. Quote:Check how "robust" was Spinosaurus: Volumetrics don't lie, and not only is that Tyrannosaurus horribly inflated the corrected volumetric models put it WELL below Spinosaurus sizewise. And for the last time, robusticity is about shape, not size! A much smaller animal can easily be far more robust than a larger one, but that does not change the fact that it is smaller. Quote:Under this point of view, to compare Spinosaurus to T. rex is like to compare a bear with a seal, there are completely different animals in completelly different habitats and we know that no one says that seals are the biggest carnivores (even when elephant seals are much bigger than the largest bears), that title belong to the bears. So been an aquatic and piscivore animal, is no longer a candidate for the largest carnivore at LAND. I'm referring to all giant theropods regardless of terrain. If we're only talking land theropods then sure we can exclude Spinosaurus, but here I'm discussing all theropods, and simply being aquatic does not exclude Spinosaurus by any means. Quote:Checking the evidence and leaving aside any "amateur" conclution, the fossils shows that T. rex was more robust than any Carcharodontosaurid, that Giganotosaurus was longer but not heavier (not even close) and that Carcharodontosaurus was smaller than all these species, even smaller than Mapusaurus. This modern reconstructionfrom 2020 show it very well, in total length terms at least: Once again, I want some explanations for WHY the estimations that put Carcharodontosaurus, Giganotosaurus, Spinosaurus, and Mapusaurus well above Tyrannosaurus sizewise are supposedly so wrong. What you're basically doing is dissing my estimates because they don't fit what you had in mind beforehand, and you're choosing less anatomically accurate models simply due to lower results. |
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