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| Spinosaurus aegyptiacus v Tyrannosaurus rex | |
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| Tweet Topic Started: Jan 7 2012, 02:16 AM (459,114 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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| Ceratodromeus | Jun 29 2015, 03:15 AM Post #4006 |
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Aspiring herpetologist
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Think its already been explained most of those specimens are dubious or the weight figure is blatantly wrong(sue being th exception I guess) However I do not intend to get into this discussion ATM. |
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| Agentjaguar | Jun 29 2015, 12:44 PM Post #4007 |
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Herbivore
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@ Spartan Being simply "spectacular" versus being a "spectacular killer" are two different things. Spino was not the latter. |
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| bone crusher | Jun 29 2015, 02:32 PM Post #4008 |
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Heterotrophic Organism
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There's no weight figure for those specimens yet, at least not from Hartman or Hutchinson. But they are at least Sue sized length wise, so the weight figure should be up there more or less. Regardless, there's no reason not to believe so since a t rex at Sue's age could typically reach this weight. It's just what we found so far comprised of much younger rexes mostly. |
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| DarkGricer | Jun 29 2015, 02:44 PM Post #4009 |
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Omnivore
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Which we know, because Sue is the only T.rex known to be around that age range.
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| bone crusher | Jun 29 2015, 03:26 PM Post #4010 |
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Heterotrophic Organism
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Er yeah but that doesn't exclude younger t rexes reaching or exceeding Sue in size. Another possibility is t rex probably reached Sue's size or greater way before 28 years old, the ones we found so far are simply less than average sized specimens? Thus explaining the existence of younger t rexes that of Sue's size.
Edited by bone crusher, Jun 29 2015, 03:27 PM.
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| Grimace | Jun 29 2015, 03:56 PM Post #4011 |
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Kleptoparasite
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I still say this fight isn't possible to call without knowing the behavior of the two animals. For all we know spinosaurus was extremely good at whipping its head down and latching onto the underside of the neck of large predators or something. Or could have been extremely hesitant to confront things, who knows. |
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| Thalassophoneus | Jun 29 2015, 05:43 PM Post #4012 |
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Pelagic Killer
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Spectacular killer of fish? Spinosaurus was just like a large crocodile. It was finding creatures ashore and pulling them in the water to kill them. Don't forget that it was mostly aquatic, which means not exclusively aquatic. Tyrannosaurus was killing Triceratops cause they were relatively sluggish animals. |
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| DarkGricer | Jun 29 2015, 05:50 PM Post #4013 |
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Omnivore
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And by those younger, Sue size (Or greater) T.rexes, do you mean the ones known from tiny little fragments that probably didn't actually come from giants, or might not even have been from a T.rex? |
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| bone crusher | Jun 29 2015, 07:07 PM Post #4014 |
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Heterotrophic Organism
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Nope, not even talking about the UCMP toe bone, just C.Rex, Rigby's rex, Scotty rex or even the holotype. |
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| Grimace | Jun 29 2015, 08:18 PM Post #4015 |
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Kleptoparasite
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Tyrannosaurus prey was very likely to have been much more impressive, but that means literally nothing. A cormorant could hurt you a lot worse a lot more quickly then a hawk would be likely to. |
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| Ausar | Jun 29 2015, 09:01 PM Post #4016 |
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Xi-miqa-can! Xi-miqa-can! Xi-miqa-can!
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What would be the use in doing that when you're possibly taller than you're opponent? That said, the only problems are that a) Spinosaurus' semi-aquatic habits (which will on the other hand allow it to win in sufficiently deep water) wouldn't exactly be advantageous (on land that is) and b) neither would the fact that its weapons aren't exactly the best when dealing with similar-sized opponents (the claws/forelimbs, while large and powerful respectively, still aren't primarily designed for killing and the jaws, well...). Edited by Ausar, Jun 30 2015, 04:34 AM.
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| theropod | Jun 29 2015, 09:04 PM Post #4017 |
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palaeontology, open source and survival enthusiast
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My dear bone-crushing friend. Please provide evidence that any of these are the size of sue (and if they are, that they are considerably younger and would still grow considerably). You are deluding yourself as to HOW MUCH adult T. rex still have left to grow, as well as how uniformly you are assuming they would grow regardless of their already-achieved sizes. MOR 1125 is estimated at 18-19 years old (Erickson et al. 2006, Horner & Padian 2004) and it is 10m, at best 10.5m long based on its femur length (Larson 2008, Schweitzer et al. 2008) and already in a phase of decellerated growth: "A femoral section of MOR 1125 taken along the minor axis is 21.83 mm thick, representing 10–11 years. The medullary radius of 38 mm represents 7 years (incremental factor) to 10–11 years (maximum interval), but the preserved maximum interval in this specimen is relatively low. The calculated age range of 17–22 years may be an overestimate; 18±2 years is a more constrained estimate. The outermost two or three LAG intervals are less than 1 mm thick, so the animal had effectively stopped growing at 16±2 years." –Horner & Padian 2004, p. 1877 That’s younger than any of the specimens you listed are as to my knowledge. From the same paper, p. 1878: "According to these estimates, a virtually fully grown T. rex would have been between 15 and 18 years old. (However, as the femur of MOR 1152 shows, growth can drop more precipitously than an incremental estimate suggests.) We have not found in any sectioned T. rex tibia or femur evidence of an outer acellular, nearly avascular layer Similar to the external fundamental system (EFS) (Cormack1957), that indicates effective cessation of growth." NOTE that an external fundamental system was found by Erickson et al. 2004, in none other than sue, which was not included in the above study: "Figure 1[…]c, Tyrannosaurus rib (FMNHPR 2081) showing the 15th to 19th growth lines. Inset, external fundamental system16 with nine tightly spaced growth lines, indicating late-adulthood senescence and growth-rate attenuation." Adult T. rex grow a little (it is, of course hard to pinpoint the absolute amount, and has not been attempted, which is also why you will not find serious scientists trying to extrapolate "full-grown" sizes for younger specimens the way pseudoscientists on topix and youtube like to do), but not that much (seemingly not enough to explain their variation in size), regardless of what you may have been told by fanboys. Sue may yet end up being large even for its exceptional age. If we want to be objective, we’d have to assume that large Spinosaurus specimens have an equal chance of still growing (though as I just showed, that growth would be rather negligible). Regardless of that though, we are talking about real specimens, not hypothesized extrapolations. –––References: Erickson, Gregory M.; Currie, Philip J.; Inouye, Brian D.; Winn, Alice A. (2006): Tyrannosaur Life Tables: An Example of Nonavian Dinosaur Population Biology. Science, Vol. 313 (5784) pp. 213-217 Erickson, Gregory M.; Makovicky, Peter J.; Currie, Philip J.; Norell, Mark A.; Yerby, Scott A.; Brochu, Christopher A. (2004): Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs. Nature, Vol. 430 (7001) pp. 772-775 Horner, John R.; Padian, Kevin (2004): Age and growth dynamics of Tyrannosaurus rex. Proceedings of the Royal Society B, Vol. 271 (1551) pp. 1875-1880 Larson, Peter (2008): Variation and Sexual Dimorphism in Tyrannosaurus rex. In: Larson, Peter; Carpenter, Kenneth: Tyrannosaurus rex the Tyrant King. Bloomington pp. 103-128 Schweitzer, Mary H.; Wittmeyer, Jennifer L.; Horner, John R. (2008): One pretty amazing T. rex. In: Larson, Peter; Carpenter, Kenneth: Tyrannosaurus rex the Tyrant King. Bloomington pp. 92-100 Edited by theropod, Jun 29 2015, 09:08 PM.
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| bone crusher | Jun 30 2015, 12:17 AM Post #4018 |
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Heterotrophic Organism
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I did say it's a possibility, who knows how much more growth headroom a 20 or 28 year old t rex would had assuming it lived in ideal condition. A single analysis from MOR 1125 is not nearly enough to conclude anything. You can randomly find an old man of 5.5 ft tall but you can't possibly determine a healthy population of 6ft+ male without seeing them for yourself first. It's way too soon or foolish to give a weight range of upper or lower bound to t rex based on the very limited and different aged samples that we have. Size wise, MOR 1125 has corresponding bones larger than Sue's (8-12% bigger?) if that still hasn't changed it would strongly imply a Sue sized rex or bigger. MOR 980 Peck's rex is said to be much more hulking than CM 9380 which is mounted right next to it, so certainly a big rex. While the holotype itself is 11.9m long and that's definitely approaching Sue's size 12.3m. Scotty rex is another 12m t rex so it's in the same ball park. Mor 980 on the far right vs CM 9380 on the left. http://dinosours.files.wordpress.com/2011/02/img_2602.jpg |
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| Spinodontosaurus | Jun 30 2015, 01:05 AM Post #4019 |
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Herbivore
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MOR 1125 is one of the smallest, if not the smallest adult Tyrannosaurus specimen known, it's femur is only 107 cm long. Sue's femur is 131 cm. MOR 980 is comparable in size to specimens like BHI 3033 (Stan), AMNH 5027 and CM 9380, all sub-12 meter specimens below the size of Sue. "Scotty" has a 129 cm femur, slightly smaller than Sue's 131 cm, slightly bigger than CM 9380's 127 cm femur and Stan's 128 cm femur. I don't know where you found the 12 meter estimate from, but it sounds roughly on the money, being as big or slightly bigger than the sub-12 meter specimens listed above, but slightly smaller than Sue. |
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| bone crusher | Jun 30 2015, 01:18 AM Post #4020 |
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Heterotrophic Organism
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Well Hartman puts Stan at 10.9m while both AMNH and CM 9380 are roughly 11.9m, huge difference. So I don't know where do you put MOR 980 at unless something's changed. I've seen Scotty Rex in my local museum and it lists it at 12m as one of the largest t rex. Do you have more data on Mor 980 by the way? |
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