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Tyrannosaurus rex
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@DinoFan83 : I just repeat what you told at #163 in this topic:
" I agree with you on that. Tyrannosaurus' skull, torso, and limb bones do seem to be a good bit more chunky and robust relative to their dimensions than those of Giganotosaurus. Speed should be similar for both. " You wrote that by seeing two photos showing each one of these predators. Clearly the T-rex's bones show that it was the most powerful predator, and this by far. Giganatosaurus and carcharondotosaurus could be longer but their bones structure were clearly slender. I'm just considering what I see by saying that. As concerns the spinosaurus, if this animal was a 100% aquatic predator, this question is from now on irrelevant. The spinosaurus's ribs and bones don't need to be as robust as the t-rex's and we saw it was quite the case (see at #110 of this topic). Comparing t-rex and spinosaurus becomes as irrelevant as comparing a t-rex and a marine reptile, even though the spinosaurus is indeed the longest and this by far. I'm agree with @GuateGojira , T-rex having appeared a long time after Giganatosaurus and Spinosaurus was the terminal form of the big dinosaurs predators, thus the most evolved and performing one, before their brutal extinction. 
@Spalea
I think you are misunderstanding what I meant by that. Nowhere did I say that Spinosaurus nor the aforementioned carcharodontosaurids were smaller than Tyrannosaurus. What I said was that Tyrannosaurus was more robust than they were, which can be true whether or not Tyrannosaurus happened to be smaller or larger. Going by an animal's build alone can be very misleading; for example, comparing the femur of Triceratops with the femur of Antarctosaurus giganteus, you'll notice Triceratops is the more robust of the 2. However, no matter how much more heavily built it is, in no way is an 8-14 tonne ceratopsian larger than a 69 tonne titanosaur, and it's similar here. Spinosaurus and the giant carcharodontosaurids, despite the fact that they seem to be quite larger than Tyrannosaurus, are less robust than it. Simple as that.  (10-16-2020, 04:35 AM)DinoFan83 Wrote: I strongly, strongly, strongly disagree with this. As I have went over earlier in this thread, the average Tyrannosaurus is approximately 6 tonnes and Sue is most likely around 7.9 tonnes (the 9 tonne estimates are most likely incorrect; I can explain if needed). The bait: In the past, when peter and I participated in the old AVA forum and saw all the dissaster that the "fanatics" of some animals can cause, we learned how to identify this tipe of persons in order to cut they lies and exagerations. Like in the hunt of an animal, the first thing that we do is to place a bait (this post in this case). We identify the best place to put it (the area that is more common to it, in this case the Dinosaurs area) and the bait is something that attract it or that irritate it (T. rex in this case). After that, is only a matter of time and eventualy the beast arrive. The capture: I was incredibly impresed that you reacted to this post in less than 5 minutes and since the beggining of your post (You say: "I strongly, strongly, strongly disagree with this.") I can see that we are treating with a fanatic here. I had saw lion-fanatics, bear-fanatics and even shark-fanatics but none of them jumped as fast as you have done today. So I think I got you here. The analysis: I had checked all your posts here and is very clear to all of us that you had a grudge agains the T. rex. I don't know what are your reasons but certainly there is a clear hate from your part for a animal that had not done anything against you, (dude, the poor animal is extinct!) but that you constantly downgrade with now special reasons, and your only backgrown are the posts of the person nicknamed "Spinoinwonderland" in Devianart. Interestingly is the fact that while you copy-paste what he/she says, you don't put the links to show also the conversations in his creations, so all the posters can see the answers of several posters that are not agree with the conclutions of this person. I see that you contantly downgrade the T. rex but you upgrade the large Carcharodontosaurids with no special reason. So I observed you, specially in your last posts about Carcharodontosaurus and Spinosaurus, and is very clear that your data do not have any base, except for the posts of Spinoinwonderland of course. The information: 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). 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. 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? 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.  *This image is copyright of its original author With this size, this animal was smaller than the Giganotosaurus holotype, so certainly it will weigh less. Check that even the holotype is so incomplete that the estimation of the weight of the biggest Carcharodontosaurus is just a guess from the guess! Only thing that we can say is that based on the few available evidence (the skull size) this animal was smaller than the Giganotosaurus holotype. Original skull:  *This image is copyright of its original author Reconstructed by Franoys without the "Pinocchio nose":  *This image is copyright of its original author 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  *This image is copyright of its original author 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. Check this other reconstructions:  *This image is copyright of its original author  *This image is copyright of its original author This accurate reconstruction shows the huge size of this animal, but also its lower body mass compared to T. rex. Finally what we normally see is this type of comparison in your claims:  *This image is copyright of its original author But you never mention this:  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author And take in count that this image is using the overestimation of the specimen MUCPv-95:  *This image is copyright of its original author So as we can see, they are using the overestimation of the sizes for Giganotosaurus and Carcharodontosaurus and even then, they look much lighter. 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:  *This image is copyright of its original author Apart from the estimation of Franoys, all the other estimations that I found shows that this animal was no more than 5 metric tones. 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. 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. 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. By the way, I still don't see any explanation about WHY Spinoinwonderland reconstructed in a completelly different form the tail of Spinosaurus: New reconstruction:  *This image is copyright of its original author The reconstruction of Spinoinwonderland with the incorrect tail form:  *This image is copyright of its original author GetAwayTrike made it much better, even when its sale is weird:  *This image is copyright of its original author At the end, even if Spinosaurus reached the 9 tons of T. rex, 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! Check how "robust" was Spinosaurus:  *This image is copyright of its original author  *This image is copyright of its original author By the way, the modern model do not change anything of the body, just the tail, so this last comparison is still acurate. Side images may deceive, but when we see it in 3D then we can appreciate the difference in mass and robustness. The Spino was escalated at 15 meters, the T. rex at 12.3 meters. 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. Conclution: 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:  *This image is copyright of its original author At the end, all this information are just educated guesses, specially for the mos incomplete specimens. Even in the more complete specimens, we don't know the true length of the tail of T. rex (for those that don't know it, there is no complete tail of this species at this moment) and we will need more specimens of Giganotosaurus. At then end, the few evidence suggest that Spinosaurus is disqualified for been mostly aquatic (although is the longest one [not heaviest, yet], than Giganotosaurus is aparently the longest one and T. rex is the heaviest one. Any out of this, is pure speculation. (10-16-2020, 05:38 AM)DinoFan83 Wrote: Going by an animal's build alone can be very misleading; for example, comparing the femur of Triceratops with the femur of Antarctosaurus giganteus, you'll notice Triceratops is the more robust of the 2. However, no matter how much more heavily built it is, in no way is an 8-14 tonne ceratopsian larger than a 69 tonne titanosaur, and it's similar here. Spinosaurus and the giant carcharodontosaurids, despite the fact that they seem to be quite larger than Tyrannosaurus, are less robust than it. Simple as that. That comparison is not even logic. We do know that those bones are NOT of the same length and not from similarly build animals. So your example is based in simple eye-sight with no information and that is not the case with T. rex and the Carcharodontosaurids. We DO KNOW the length of the long bones of T. rex and Giganotosaurus and those of T. rex are more robust, in fact the entire skeleton is more robust. The comparison with Spinosaurus is similar, but with the entire skeleton and side by side T. rex is far more massive. In this case, Giganotosaurus is a best second place for the heaviest land carnivore dinosaur, Spinosaurus is an aquatic animal based in the evidence. This massivenes can't be compared with any other carnivore dinosaur:  *This image is copyright of its original author  *This image is copyright of its original author
@DinoFan83 :
I repeat you at #195: " Considering all this, I see absolutely no reason to think Tyrannosaurus was the largest carnivorous dinosaur ever discovered seeing as based on all of this, Spinosaurus, Giganotosaurus, Mapusaurus, and Carcharodontosaurus all appear to have been SUBSTANTIALLY heavier. " And you, speaking about the " aforementioned carcharodontosaurids " at #197 : " What I said was that Tyrannosaurus was more robust than they were, which can be true whether or not Tyrannosaurus happened to be smaller or larger. " T-rex wasn't the longest but the most robust, right ? Thus, if carcharodontosaurus, gigatonosaurus and mapusaurus were indeed a little bit more longer than the T-rex, it's impossible they were substantially heavier given their more slender bones structure. CQFD as we say in french language... What it needed to be demonstrated. When we don't stop to see photos demonstrating T-rex had the most robust bones structure among the big dinosaur predators on land on this by far, no use henceforth to pick here and there some figures enabling to proove the opposite. The carcharodontosaurids couldn't be substantially heaver than the t-rex, because they were only a little bit larger. And because we were going to speak about beast of the same family (Carnosaurids), thus your analogy, at #197 too, with the triceratops's and antarctosaurus's femurs is completely irrelevant.
I had a really, really, really big reply to GuateGojira in the works but it got deleted. I'll need a moment to rewrite it.
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.
@DinoFan83
"More robust" implies at equal length, the T-Rex is heavier than the carcharodontosaurus and giganatosaurus, OK? With a little bit logic, you can easily admit that especially if you always consider the T-Rex as being more robust. Thus being only a little more longer, your beloved carcharodontosaurids cannot be "substantially heavier" than the T-Rex, it's impossible.
@Spalea
The disparity is not so great that a little length advantage cannot make up for a less robust build, regarding the carcharodontosaurids. For example, Greg Paul's Giganotosaurus is about 12.45 meters long for the holotype going by his megafauna size chart in the 2016 Princeton Field Guide to Dinosaurs, and his skeletal of MUCPv-Ch1, when correcting the pectoral girdle, is 8.17 tonnes (this puts Giganotosaurus as well as probably Mapusaurus and Carcharodontosaurus on a similar level of robusticity to Tyrannotitan). And SpinoInWonderland's Giganotosaurus GDI's are approximately the same as that - 12.32 meters and 7.53 tonnes for his GDI of GetAwayTrike's Giganotosaurus as well as 12.2 meters and about the same mass for his own skeletal. These animals really don't need THAT much length advantage to be larger than Tyrannosaurus, not at all. 
In this debate, please avoid using a condescending tone and other derogatory words. I say this generally.
@DinoFan83, are you aware of source that has photo or measurements of therapod mandibula? I ask because the larger Giganatosaurus fragment is often said to be larger due to chance and not larger skull (which as you've mentioned can go the other way too). However in cats, the larger the horizontal ramus (akin to the dentary), the proportionately larger the skull. In other words, the ratio of skull length to horizontal ramus length is higher the largest the animal gets. I want to test this in therapods. Also, apologies for me missing this, but could you please direct me to a read showing T. rex as overinflated? Thanks for sharing newer aspects of discussions in the dinosaur community here. (10-16-2020, 10:39 PM)tigerluver Wrote: @DinoFan83, are you aware of source that has photo or measurements of therapod mandibula? I ask because the larger Giganatosaurus fragment is often said to be larger due to chance and not larger skull (which as you've mentioned can go the other way too). However in cats, the larger the horizontal ramus (akin to the dentary), the proportionately larger the skull. In other words, the ratio of skull length to horizontal ramus length is higher the largest the animal gets. I want to test this in therapods. I don't think I can give you anything like that for carcharodontosaurids specifically (due to the incompleteness of their cranial material), but we can potentially compare dromaeosaurids, abelisaurids, and megalosaurids to get an idea of what trends carcharodontosaurids may follow regarding the horizontal ramus vs proportional head size. Dromaeosaurids: Comparing Scott Hartman's skeletal of Dromaeosaurus to his skeletal of Utahraptor, the mandibular ramus structure of both animals appears to be very similar despite the skull of Utahraptor being considerably larger proportionally. If anything the Dromaeosaurus' ramus may be larger despite its smaller head. Abelisaurids: Comparing GetAwayTrike's Carnotaurus skeletal to Blazze92's skull reconstruction for Ekrixinatosaurus (the latter has a proportionally larger head by quite a bit), there don't appear to be any major differences for the ramus size proportionally. Megalosaurids: Comparing my cross scaling for Megalosaurus (GetAwayTrike+Scott Hartman composite) and GetAwayTrike's Torvosaurus (the former has a head about 10.9% larger proportionally), the proportional size of the ramus remains similar once again. While we can't make any definitive conclusions until we have more complete cranial material from carcharodontosaurids, I would say that going by the trends of some other theropods, carcharodontosaurids did not have the same ramus trends as cats did. Quote:Also, apologies for me missing this, but could you please direct me to a read showing T. rex as overinflated? Thanks for sharing newer aspects of discussions in the dinosaur community here. No problem. Hutchinson et al. 2011 (the study where my corrected estimate of 7.47 tonnes for Sue is based on) states that: "the torso of the mount is inflated in width due to a dorsal displacement of the transverse processes on the trunk vertebrae, which forced a dorsal displacement of the tubercular articulations and a lateral expansion of the rib cage as a whole." The dorsal ribs on the mount are also strongly swept anteriorly instead of strongly posteriorly as they should be, which inflates the torso's volume further still.
@DinoFan83 :
About #204: I just believe we're confusing different parameters. I have no difficulty to admit than carcharodontosaurus and giganatosaurus were a little bit larger than t-rex (and since the spinosaurus was a fully-aquatic animal, these carcharodontosaurids were the largest known dinosaurs predators on land). But their length differences with the t-rex aren't enough great to say "they were substantially heavier", especially as the t-rex was more robust. They would really have had to be substantially longer to be substantially heavier. "More robust" implies a bones structure more massiv in order to support more muscle (at equal length, t-rex is pound for pound stronger, thus more robust). And when we see a t-rex's skull or a t-rex's femur compared to those' of these carcharodontosaurids, they are clearly more massiv. So...
The reason why they are so much heavier is because volume increases to the cube of length, and therefore there's less of a length advantage needed than you think for a large mass estimate. Giganotosaurus could very well get up to 13.45 meters and Mapusaurus up to 13.7 meters. Based on Scott Hartman's rather underestimated Giganotosaurus (12.4 meters, 6.8 tonnes), they would be 8.68 and 9.17 tonnes respectively (already quite substantially heavier than the 7.9 tonne Sue), and with Greg Paul's corrected skeletal (12.45 meters, 8.17 tonnes), this gets higher still, at 10.29-10.87 tonnes. Now can you see how these carcharodontosaurids can be so much heavier?
(10-17-2020, 12:00 AM)DinoFan83 Wrote: The reason why they are so much heavier is because volume increases to the cube of length, and therefore there's less of a length advantage needed than you think for a large mass estimate. Giganotosaurus could very well get up to 13.45 meters and Mapusaurus up to 13.7 meters. Based on Scott Hartman's rather underestimated Giganotosaurus (12.4 meters, 6.8 tonnes), they would be 8.68 and 9.17 tonnes respectively (already quite substantially heavier than the 7.9 tonne Sue), and with Greg Paul's corrected skeletal (12.45 meters, 8.17 tonnes), this gets higher still, at 10.29-10.87 tonnes. Now can you see how these carcharodontosaurids can be so much heavier? No ! You're wrong. The volumes increases to the cube of the length only if these animals are built on the same way. Giganatosaurus and carcharodontosaurus are indeed longer, but significantly less wider. See them face on and compare with the t-rex. It's blatant on the photo !  *This image is copyright of its original author
Quote:No ! You're wrong. The volumes increases to the cube of the length only if these animals are built on the same way. Actually, no. The volume increases with the cube of length regardless of the build of the animal. Let's take MUCPv-Ch1 and MCF-PVPH-108.145 as an example. Since MCF-PVPH-108.145 is most likely 10% larger than MUCPv-Ch1 in all dimensions, it would be 10% longer, 10% wider, and 10% taller. Therefore when scaling up, you need to cube the mass to account for that. 8.17 tonnes x 1.1^3=10.87 tonnes. This will hold true of any animal you isometrically scale regardless of how bulky or gracile it may be. Quote:Giganatosaurus and carcharodontosaurus are indeed longer, but significantly less wider. See them face on and compare with the t-rex. It's blatant on the photo ! Haven't you seen me address this? That Tyrannosaurus is overestimated sizewise due to the ribcage being too wide and the ribs not being swept back properly, while the Giganotosaurus is underestimated due to the incomplete scapula being taken as complete and therefore the very shallow chest. Moreover, while carcharodontosaurids were not as wide proportionally as tyrannosaurids they tended to be rather deep chested. Check out SpinoInWonderland's Giganotosaurus or his GDI of GetAwayTrike's skeletal for example - these shows how deep the torso is when correcting the scapula and that is one of the factors that contributes to the large size of giant carcharodontosaurids. |
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