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| Spinosaurus aegyptiacus v Tyrannosaurus rex | |
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| Tweet Topic Started: Jan 7 2012, 02:16 AM (459,312 Views) | |
| Wolf Eagle | Jan 7 2012, 02:16 AM Post #1 |
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M E G A P H Y S E T E R
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Tyrannosaurus rex Tyrannosaurus is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning "king" in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 67 to 65.5 million years ago.[1] It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators. By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and ceratopsians, although some experts have suggested it was primarily a scavenger. The debate over Tyrannosaurus as apex predator or scavenger is among the longest running in paleontology. Tyrannosaurus rex was one of the largest land carnivores of all time; the largest complete specimen, FMNH PR2081 ("Sue"), measured 12.8 metres (42 ft) long, and was 4.0 metres (13.1 ft) tall at the hips. Mass estimates have varied widely over the years, from more than 7.2 metric tons (7.9 short tons), to less than 4.5 metric tons (5.0 short tons), with most modern estimates ranging between 5.4 and 6.8 metric tons (6.0 and 7.5 short tons). Packard et al. (2009) tested dinosaur mass estimation procedures on elephants and concluded that dinosaur estimations are flawed and produce over-estimations; thus, the weight of Tyrannosaurus could be much less than usually estimated. Other estimations have concluded that the largest known Tyrannosaurus specimens had a weight exceeding 9 tonnes. ![]() Spinosaurus aegyptiacus Spinosaurus is a genus of theropod dinosaur which lived in what is now North Africa, from the lower Albian to lower Cenomanian stages of the Cretaceous period, about 112 to 97 million years ago. Spinosaurus may be the largest of all known carnivorous dinosaurs, even larger than Tyrannosaurus and Giganotosaurus. Estimates published in 2005 and 2007 suggest that it was 12.6 to 18 metres (41 to 59 ft) in length and 7 to 20.9 tonnes (7.7 to 23.0 short tons) in weight. The skull of Spinosaurus was long and narrow like that of a modern crocodilian. Spinosaurus is thought to have eaten fish; evidence suggests that it lived both on land and in water like a modern crocodilian. The distinctive spines of Spinosaurus, which were long extensions of the vertebrae, grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display. Dal Sasso et al. (2005) assumed that Spinosaurus and Suchomimus had the same body proportions in relation to their skull lengths, and thereby calculated that Spinosaurus was 16 to 18 meters (52 to 59 ft) in length and 7 to 9 tonnes (7.7 to 9.9 short tons) in weight. The Dal Sasso et al. estimates were criticized because the skull length estimate was uncertain, and (assuming that body mass increases as the cube of body length) scaling Suchomimus which was 11 meters (36 ft) long and 3.8 tonnes (4.2 short tons) in mass to the range of estimated lengths of Spinosaurus would produce an estimated body mass of 11.7 to 16.7 tonnes (12.9 to 18.4 short tons).
Edited by Taipan, Apr 24 2015, 10:10 PM.
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| theropod | Dec 23 2012, 07:40 AM Post #1036 |
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palaeontology, open source and survival enthusiast
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It is actually not that much different, proportions stay about the same, it has a slightly altered shape but not that much actually. the quadrate and quadratojugal don´t reach as far back in those pictures you posted and the posterior skull is deeper. It doesn´t really affect lenght. Also, parts of Suchomimus postorbital skull are known, see it here: http://home.arcor.de/rocksquarter/se468700602a.jpg It isn´t as complete as Irritator of course but it isn´t all guesswork and more than one might think. Edited by theropod, Dec 23 2012, 07:41 AM.
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| MysteryMeat | Dec 23 2012, 07:49 AM Post #1037 |
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Herbivore
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There's no postorbital, squamosal, and only a finger tip sized jugal, and half of a quadratojugal. So it is largely guess work. Even if you happen to get the length in the ball park, the shapes are all wrong. |
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| Fist of the North Shrimp | Dec 23 2012, 07:54 AM Post #1038 |
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vá á orminum
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No, but I want you to stop prosyletiting your opinion as fact without having a proper base. And surely I am the lazy one, I could quit searching the web for stuff alltogether. But this is not the first time you ignore the evidence others post just because you want to. I could post skeletals for Angaturama and detailed images of the preserved skull bones, but I guess you would just ignore them just because they do not fit your opinion. I think I can spare myself that work. LOL what is more distantly related to you? And if you would bother to look behind raw similarities, you would see that this statement is utterly wrong. And the point about Geographic range is Hilarious in the light of phylogenetics. And how can you even claim all that similarities for Spinosaurus while currently only very few material has been described?
And it could be an adult. And it could be a hoax. And it could be a joke from sapient Spinosaurids One possible explanation for its different proportions? mhh, what about milions of years of divergence and belonging to another clade? And there is information on them out there, but you already contradict yourself below(first, it is not desribed enough and then suddenly you have no access to actual information, in the same post?). I cannot take your written word honest then.
And here we see, you work is redundant because someone else already made an more accurate reconstruction. But unfortunately you lack the resource to do so yourself, or simply fail at hunting papers. And you do not need to buy an expensive paper to make me happy, you should just cease to acclaim your opinion as unfaillable truth. You are putting your own opinion over peer reviewed papers and other posters arguments. This is, politely expressed, extremely rude towards other posters. I think that Spinosaurus reached around 15 meters but I accept a wider range of estimates as equally propable. And if there is doubt about something than WFTP. If you think that an animal which has some blatant differences in comaprison with another animal is a good analogue, then I can help you even less. |
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| theropod | Dec 23 2012, 08:03 AM Post #1039 |
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palaeontology, open source and survival enthusiast
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There also happen to be most of the posterior bones located at the skull roof so it is by far not as inclomplete as you claim. the quadratojugal might have been positioned differently-or maybe just like reonstructed there, who knows, the lenght however is absolutely correct, so are frontals, parietals, occipital, the quadrate etc. What´s mainly missing are the jugals, the postorbitals and the squamosals. it looks more incomplete than it really is. And the shape is only slightly different in Irritator (one more thing suggesting these animals are all pretty similar), the lenght is similar, the basic proportions and shapes are similar. of course they don´t look the same, of course the quadratojugal has a different rotation and some of the bones are located differently and the posterior cranium is a bit deeper, but it is nothing dramatic. The snout shape of Spinosaurus just imo happens to fit the shape reconstructed there better than a deeper one, just my opinion and nothing to argue about. If you seriously think some minor differences (that btw are normal between different species) are so dramatic you can do your own reconstruction, don´t you? http://www.sciencemag.org/content/282/5392/1298.full |
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| Carcharadon | Dec 23 2012, 08:13 AM Post #1040 |
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Shark Toothed Reptile
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Spinosaurus don't have "incredibly weak jaws". It actually has a strong bite, it does take strength to hold on to 8 m sawfish |
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| MysteryMeat | Dec 23 2012, 08:21 AM Post #1041 |
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Herbivore
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The lateral side of the the skull, behind the lacrimal, is largely unknown. All the missing parts I listed are correct. The back half of the skull is almost twice as deep as around the orbit as the snout, constructed based on Irritator. In your image, it's maybe 25% deeper. That's not a slight difference. And it is not just normal difference between species. I don't think anyone thinks Suchomimus and Spinosaurus only has specific level difference, they don't belong to the same genus, it's sub-family level. I will do my own reconstruction, and I would use Irritator as my reference. It would come out roughly the same as Del Sasso's reconstruction. But for now, my goal is to reconstruct Acrocanthosaurus. Spinosaurs are gonna have to wait. Edited by MysteryMeat, Dec 23 2012, 08:25 AM.
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| theropod | Dec 23 2012, 08:21 AM Post #1042 |
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palaeontology, open source and survival enthusiast
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@MantisShrimp: I´m not making my opinion fact, unlike you who think once you don´t agree with something all others should have the same opinion as you and do what you suggest.
You always do, why do you think am I the one always making the whole work and you are the one yelling at me once you spot something you don´t agree with?
The wide majority of specimens and scientists seemingly agrees about that, it is frankly not my problem and not even relevant to what I made the reconstruction for...
I´m starting to believe you are such a (semi-)sapient spinosaurid
or maybe it is just you who reads to fast because even before finishing you already know what to reply... I don´t have access to the description paper of Irritator, while the skeleton you are talking about wasn´t described at all If there is anyone who is constantly ridiculing himself with predictable and pointless posts, it is you.
you fail to understand what this is all about, I made a reconstruction based on how suchomimus was reconstructed because of two reasons: -it is suchomimus and baryonyx that I have also used for the size estimates, so this is simply most closely related to size. -I think it seems a likely shape for the skull regarding the shape of the reported part your post is redundant, not my reconstruction
If I had only ever claimed so, when have you seen me doing that? Isn´t it you who is so sure of himself being right all the time that you cannot stop judging about others? I gave a very simple and easy-to-understand statement, that Dal Sassos estimate cannot be regarded as debunked. This is indeed a fact, all else is my opinion based on logical considerations (compare that to your opinion which is only based on an urge to disagree with me). Of course I think I am right, otherwise why should I agrue anything? That is not the same as making my opinion fact.
Politely expressed, you are not in a position to seriously tell others they where rude towards other posters. Mantis shrimp, I am telling you this for the last time before putting you on my ignore list: PLEEEASE stop misinterpreting what I write, twisting my words, then telling me I was writing BS and making it fact, ignoring whatever argument I give you and then call ME rude. If you have problems with me, send me an E-mail and give me a nice long list and I will reply to them, but not here, in a place devoted to proper scientific discussions and not your personal hatred. I have tried to have civil debates with you over and over again, and every single time you just cannot accept others opinions and the difference between having an opinion and enforcing it upon others. Edited by theropod, Dec 23 2012, 08:34 AM.
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| theropod | Dec 23 2012, 08:33 AM Post #1043 |
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palaeontology, open source and survival enthusiast
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I didn´t say they wheren´t, but there are some important parts actually reported. Everyone can make an own reconstruction, it is not as if there was a right or a wrong one by now, and there are already enough different ones even for Sucho and Baryonyx. Looking forward to yours. I chose a more slender posterior part matching the slender snout. if one removes that difference, they are still very similar. Such factors can vary a lot, just look at the skull variation in modern crocodilians. it is not things like skull depth that set taxa apart, they are often completely different. It´s the smaller less obvious elements in a skulls built that actually matter for taxonomy and systematics. These are not drastically different, whether you look at Irritator or Suchomimus. |
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| theropod | Dec 23 2012, 08:54 AM Post #1044 |
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palaeontology, open source and survival enthusiast
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![]() here, for those who want a more Dal Sasso oriented one. When I made the skull reconstrucction I knew some might don´t like it, but that amount of hostility indeed surprised me, I would ahve expected that at least some people would see it and regard it as what it is-a reconstruction- and not some sort of insult and "making my opinion fact". |
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| Fragillimus335 | Dec 23 2012, 09:06 AM Post #1045 |
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Omnivore
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I like the proportions of this one even more! I think Spino's skull was a little more robust than Suchomimus's, and this reconstruction better displays it. If it wouldn't be too much trouble, could you do a mandible to match this one? I have absolutely zero digital art skill.... |
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| MysteryMeat | Dec 23 2012, 09:09 AM Post #1046 |
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Herbivore
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I don't think you can draw conclusions just base on the general shape of the snout. All these Spinosaurs we know have long slender snouts. But within that snout, the bones have very different proportions. Sucho premaxilla makes up for more than half of the naris. While Spino's premaxilla is way more elongated, and it doesn't even touch the naris. Spino's naris is set far far away from the tip of the snout. That's one huge difference between the two. There's also tooth count differences in the premaxilla and maxilla. Suchominus seems to have one more tooth on the premaxilla, and probably a lot more teeth on the maxilla. Irritator is something in between, but seems to resemble Spino more. The tooth row ends around where the anteorbital fenestra is. The naris opening is not as close to the tip of the snout as Baryonychins. I think Spino is just special in its super elongated snout. |
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| theropod | Dec 23 2012, 09:23 AM Post #1047 |
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palaeontology, open source and survival enthusiast
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The rostrum in spinosaurus is definitely shallower than in Suchomimus or Baryonyx, it cannot only be seen when comparing the Spinosaurus rostrum to the respective part in Baryonyx, it is also seen in this study: http://www.academia.edu/1812192/Structural_performance_of_tetanuran_theropod_skulls_with_emphasis_on_the_Megalosauridae_Spinosauridae_and_Carcharodontosauridae That´s where I first really saw a comparison of the two noticing how much deeper the rostrum of Baryonyx is. The superficial proportions are not what is of great scientific importance in determining relationships, such things vary rapidly. Guys (especially Mantis Shrimp), just don´t get upset once someone makes a reconstruction that looks different from what you are used to! No-one forces you to favour it over others and if you have already problems accepting the existence of skull reconstructions, that are speculative anyway, that don´t look the same as animal X, how can you seriously accept the existence of things like the size estimates for Leedsichthys??? Fragillimus: Yeah, I could do a mandible. I´m a bit busy at the moment but it isn´t difficult. You could easily do it yourself tough, this is not what one can call art, Inkscape is one of the most easy to use programs out there. http://sourceforge.net/projects/inkscape/files/inkscape/ |
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| Fragillimus335 | Dec 23 2012, 11:07 AM Post #1048 |
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Omnivore
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I don't know how much I trust that study. It says it started by loading the Spinosaurus skull in a different area than all the other skulls, that instantly makes the results less correlative. It also bases the scaling on skull surface area, which Spinosaurus is lacking, but it's snout is nearly solid bone compared to the fenestrae filled skulls of the other theropods in the study. But I'm not an expert... so, just things to consider. |
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| dinosaur | Dec 23 2012, 11:46 AM Post #1049 |
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Heterotrophic Organism
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Does anybody agree Tyrannosaurus kills Spino? |
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| dino-ken | Dec 23 2012, 11:51 AM Post #1050 |
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Herbivore
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At present - I would say about 57% of these who have voted agree with that statement.
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