| Welcome to Carnivora. We hope you enjoy your visit. You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile and voting in polls. Registration is simple, fast, and completely free. Join our community! If you're already a member please log in to your account to access all of our features: |
| Spinosaurus aegyptiacus v Tyrannosaurus rex | |
|---|---|
| Tweet Topic Started: Jan 7 2012, 02:16 AM (459,177 Views) | |
| Wolf Eagle | Jan 7 2012, 02:16 AM Post #1 |
![]()
M E G A P H Y S E T E R
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
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.
|
![]() |
|
| Replies: | |
|---|---|
| Vobby | Jan 27 2014, 01:35 AM Post #3061 |
|
Omnivore
![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
It is not that we have to religiously believe to one researcher or to another, we study both their opinions and decide what we think is more convincing. In this particular case, I absolutely don't want to deny the importance and the validity of Hartman reconstruction. I've just some problems in the fact that he isometrically scales the Milan rostrum, arriving to an animal considerably bigger than the holotype, while I find more plausible to think that skull (and remember that a lot depends on how you reconstruct it) doesn't need to scale isometrically with the body. Everyone here consider the study of Therrien and Henderson quite flawed, and in fact what they did was to try and find lenght and mass estimates from theropods skulls... Note that, if you look deeply in the confrontation between Cau's and Hartman's Spinosaurus, there are importants similarities. I think that especially one thing is important: looking here http://www.skeletaldrawing.com/home/super-spinosaurus6282013 appear very clear that both the neck and the ribcage of Tyrannosaurus are deeper in Tyrannosaurus than in Spinosaurus. Also, looking at the vertebrae's centra, we see that the lenght in the two animals are similar, while T. rex has clearly the much taller and thicker ones. So, which are the differences between Cau's and Hartman's thoughts if the arguments of the former are based on the fact that Spinosaurus was a very elongated theropod, but also a very thin one? The difference in the size of the vertebrae and the difference in the width of the torso-ribcage showed by Cau are found also if we compare the skeletal reconstruction of Tyrannosaurus and Spinosaurus made by Hartman. I don't deny that Spinosaurus was longer than T.rex, as nobody deny that, for exaple, the Giganotosaurus MUCPv-Ch1 was longer than Sue. But, as Hartman precisely showed, width seems to matter a lot when calculing volume, from which we can estimate the mass. Since Spinosaurus appears most probably longer than both T. rex and Giganotosaurus, but also definetly thinner (again, just look at the vertebrae and the ribcage) I think it was the lightest of the three. |
![]() |
|
| theropod | Jan 27 2014, 01:37 AM Post #3062 |
|
palaeontology, open source and survival enthusiast
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
If an Edmontosaurus survived facial injuries inflicted by a T. rex, this must have been either an extreme fluke or a misplaced bite. A proper bite could have crushed the skull. We know injuries T. rex inflicted on other animals, and know it was capable of driving its teeth deeply into or through bone. I recall a report that found a large Triceratops femur bitten in half by it. Spinosaurus is not comparable in the jaws department, as enough people, even fanboys, have managed to point out. This is because through its overall morphology, size and dietary preferences it does not require as much killing power concentrated in its bite. Its bite is designed for quick, precise puncturing bites to either catch fish or other mid-sized animals. Of course, one has to keep in mind "mid-sized" in relation to Spinosaurus still means "multi-ton animal", but its 1-5t, not the 8-12t of a Spinosaurus. Large fish, small to medium-sized archosaurs (ornithopods, crocodilians, pterosaurs, small sauropods and theropods). However, snake-like jaw expansion and swallowing has been proposed and rebutted for theropods on some occasions. Spinosaurus’ skull would have to be far more kinetic than it likely was to allow such behaviour, and its teeth are not suitable for it. In fact, they would be a major hindrance, since they are long and straight, some even pointing slightly forwards. For swallowing large prey whole, it would need teeth that are strongly recurved for the prey to slide backwards easily, or teeth sharp enough for them not gripping the flesh at all. It seems more likely it would dismember prey by pulling. Also the very deep shape (among the deepest theropod dentaries) of the dentary is not really consistent with a dorsoventrally weak mandible. I’m not arguing it was unkinetic, which is only reported for tyrannosaurids among theropods thus far, but it doesn’t have to be particularly thick posteriorly. After all the bones in this region form a scarf joint, its even necessary for the overlapping portions to taper. The deep shape nevertheless indicates it was somewhat resistant to bending in the sagittal plane, consistent with its purpose to catch and lift or pull something. |
![]() |
|
| theropod | Jan 27 2014, 01:46 AM Post #3063 |
|
palaeontology, open source and survival enthusiast
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
Actually hartman’s MNHM is not that much bigger, by far the smallest any researcher arrived at. as I pointed out, Dal Sasso et al. and Headden both indicate it to be ~50% bigger, and this is easy to replicate if you have a look at the dentary-rostral propostions in Suchomimus, or the postdentary-postrostral proportions of Irritator, while 20% seems to base on a 95cm dentary. Hartman has it at merely slightly above 11%, which is just insignificantly bigger than Cau’s 8%. But regardless of that, Hartman’s Spinosaurus is bigger than sue, at least unless you completely remove the neural spines.
One note: The rib in question is barely longer than the dentary. I think that somewhat calls into question whether this was really among the longer ribs of the animal. Regardless, This animal’s mass is only partly concentrated in the thorax, and it is quite doubtful whether MNHM was really only a little larger than the holotype. |
![]() |
|
| TheMechaBaryonyx789 | Jan 27 2014, 03:08 AM Post #3064 |
|
Herbivore
![]() ![]() ![]() ![]() ![]() ![]()
|
Scott Hartman's MSMN V4047 (largest Spinosaurus specimen) is in fact larger than Sue and presumably Giganotosaurus respectively. I know the image is kinda small but here are the sizes: MSMN V4047 (the largest Spinosaurus specimen)- 12.5 tons in weight Sue- 8.4 tons in weight. Edited by TheMechaBaryonyx789, Jan 27 2014, 03:11 AM.
|
![]() |
|
| Vobby | Jan 27 2014, 03:56 AM Post #3065 |
|
Omnivore
![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
Do those numbers come from Hartman himself? Has been said several times here that he still didn't published his GDI for Spinosaurus. If the author of that image just calculated the area of Spinosaurus silouhette, then it's normal for it ending up weighing more than Sue. Blaze have done a similar comparison and the holotype came out of being 6 tons, 7 at most. (By the way, regarding Sue, we should pay more attention to 9,5 t estimate from Hutchinson et al. which is very recent too and quite rigourous, it seems, and also indirectly confirmed by Bates et al.) @theropod, yes, if we ignore the neural spines both Giganotosaurus and Tyrannosaurus are bigger than Spinosaurus. So the whole debate about Spinosaurus size should be about the fact that, while the spines clearly make it dimensionally bigger, enlarging its area in the lateral view, we don't really know how much they would increase its volume. Personally, I think the spines are far too thin for having supported the kind of heavy epaxial muscolature showed by rhinos, for example. If we compare the neural spines of Spinosaurus with those of T. rex, only the latters appear thick and solid enough for having supported big muscles, and having resisted the consequencial high stress. I find likely that those spines were made for supporting ligaments and tendons attached to the neck and head to, in order to support its way of hunting-feeding. But a 8-9 tons Spinosaurus would have had 2-3 tons of muscle mass on its spines, which is impossible (and ridicoulous to imagine, since it would basically have an additional torso on its back), and I'm sure no one here has such a thing in mind... |
![]() |
|
| theropod | Jan 27 2014, 04:10 AM Post #3066 |
|
palaeontology, open source and survival enthusiast
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
Those estimates were guesstimates by Spinodontosaurus I think. Hartman has not yet finished his Spinosaurus GDI, however he promised one some time ago so I think it is also only a matter of time until it get published. Lateral area measurements are problematic here for obvious reasons. I think it’d be best to include the neural spines up to roughly half their lenght, which will suit a roughly triangular, tapering cross-section. Btw the supraspinal ligaments are a support structure for the spine, in addition one with truly huge lever arms, wouldn’t you agree? You are a too sure about your claim of both G. carolinii and T. rex being bigger though. All of this bases on the assumption that its whole torso was consistently as much smaller as the single subcomplete rib seems to show, that its lenght would not make up for that, that its epaxial musculature was minimally extensive, and that they both had the same densities. Of course on top of that the dentary is restored considerably smaller in relation to the snout than it would be based on Suchomimus... Edited by theropod, Jan 27 2014, 04:11 AM.
|
![]() |
|
| TheMechaBaryonyx789 | Jan 27 2014, 04:13 AM Post #3067 |
|
Herbivore
![]() ![]() ![]() ![]() ![]() ![]()
|
The 12.5 ton estimates for MSMN V4047 (largest Spinosaurus specimen) are derived from weight estimates for Suchomimus. And the 8.4 ton estimates for Sue are from Scott Hartman himself. I rather consider Spinosaurus (the largest specimen) to be around 11-13 tons in weight, but the subject matter is debatable. I also favour Spinosaurus in this fight. Edited by TheMechaBaryonyx789, Jan 27 2014, 04:15 AM.
|
![]() |
|
| Canadianwildlife | Jan 27 2014, 04:20 AM Post #3068 |
![]()
Apex Predator
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
Yes, it does matter! The edmosaurous is just one example, and all that is is a speculation off of a few fossils. Its bite would work if it can place it at the right time, and how in the world am I speculating, all I said was that bite force matters, whci you stated that it didn't which is wrong. Now you are speculating that bite force doesn't matter. |
![]() |
|
| theropod | Jan 27 2014, 04:25 AM Post #3069 |
|
palaeontology, open source and survival enthusiast
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
If I take of around half of the dorsal "superstructure", I get the following figures (Axial parts in Hartman’s diagram): Holotype 102601px MNHM v4047 11.40% 127327px MNHM v4047 20.00% 147745px sue being 71648px Spino/sue ratios: 1.4320148504 1.7771186914 2.0620952434 Assume MNHM is 20% narrower-bodied, it would still be heavier by a considerable margin (42%), and that’s ignoring its legs and arms would also be heavier, that it would be less pneumatic, and that this is more or less the lowest realistic relative size you can get for this specimen. Assuming 50% its still 18% heavier. Sue being heavier is unlikely if you ask me. I’d rather say that this specimen would be at least ~20-40% heavier, perhaps more, depending on the skull restoration. EDIT: If we use a width-ratio of 1.78 as in the ichthyovenator-based picture, the holotype is ~80% sue’s volume (that I presume many will agree with), and MNHM at 11.4, 20 and 50% bigger would have to be 111, 139 and 271% if my calculation is correct. Assuming Spinosaurus is 10% denser than sue (a conservative assumption), you get 122, 152 and 198% respectively. Edited by theropod, Jan 27 2014, 05:15 AM.
|
![]() |
|
| Vobby | Jan 27 2014, 05:03 AM Post #3070 |
|
Omnivore
![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
Uhm, I'm not able to do such a comparison right now, so I cannot verify why there is such a difference between you results and that of Blaze. I think it would be interesting to compare first the complete area of the silouhette, than the area with half neural spines, than the area with "normal" neural spines. By, the way, 20% narrower is unlikely, unless you think the comparison of the ribcages made by Cau completely wrong: ![]() Even with a 120% Spinosaurus, the difference isn't just 20%. Using those numbers, the wideness of Sue's torso is 152 % that of the biggest possible Spinosaurus (which is, in comparison, only 65 % that of Sue). These are quite high numbers. If we simplify the matter and hypothesize that those 180 cm and 118 cm to be diameters of a hypothetical round section of the animal's torso (not so much different from reality I guess, if you consider also the epaxial muscolature) we would have this numbers: the area of the section of Sue's torso is 25434 cm2, while that of MNHM ecc is 14949 cm2, which is less than 59 %. No, I don't really think that the additional lenght would make up for such a difference. We should really e mail Shartman and promise him some money for that GDI
|
![]() |
|
| theropod | Jan 27 2014, 05:07 AM Post #3071 |
|
palaeontology, open source and survival enthusiast
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
The last line at least we agree about
|
![]() |
|
| Hatzegopteryx | Jan 27 2014, 06:24 AM Post #3072 |
|
Unicellular Organism
![]() ![]() ![]()
|
I still don't get why you are basing those estimates from what theropod called guesstimates by Spinodontosaurus. If they haven't been calculated by him they are just guesses that can't be taken much into consideration. @Canadianwildlife: Not really, the small gape plus the bone crushing bite won't work with something larger than the animal itself, not to mention how this is not a defenceless prey item, but a theropod that fights back. You are speculating how the fight would go which is totally pointless. Biteforce does matter but not much here since... Spinosaurus: Its weaker bite won't kill the tyrannosaurid, since even BHI 3033 survived many worse pathologies Tyrannosaurus: Its gape and its bite aren't designed to be effective against larger predators, it won't be able to bite in effective areas like the neck or the skull. |
![]() |
|
| Spinodontosaurus | Jan 27 2014, 06:29 AM Post #3073 |
|
Herbivore
![]() ![]() ![]() ![]() ![]() ![]()
|
Spinosaurus would be slab-sided, like every megalosauroid, whilst Tyrannosaurus is more barrel-chested. The maximum width may be greater in the latter, but Spinosaurus' width will be more consistent across the length of the torso. Which animal is larger as a result of this isn't clear, and we would need something such as Hartman's GDI to clear it up. Also yeah those figures are very rough and I now consider them too high. Edited by Spinodontosaurus, Jan 27 2014, 06:30 AM.
|
![]() |
|
| Hatzegopteryx | Jan 27 2014, 06:32 AM Post #3074 |
|
Unicellular Organism
![]() ![]() ![]()
|
You mean the 11-13 ton estimates? |
![]() |
|
| spinosaurus rex | Jan 27 2014, 06:44 AM Post #3075 |
![]()
Carnivore
![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]()
|
despite the relations, spinosaurs are actually much more thickly bodied then other megalosauroid. so the body builds are not constant. compare suchomimus ![]() to torvosaurus
Edited by spinosaurus rex, Jan 27 2014, 06:48 AM.
|
![]() |
|
| 2 users reading this topic (2 Guests and 0 Anonymous) | |
| Go to Next Page | |
| « Previous Topic · Dinosauria Interspecific Conflict · Next Topic » |
| Theme: Dinosauria light | Track Topic · E-mail Topic |
2:23 AM Jul 14
|
Powered by ZetaBoards Premium · Privacy Policy


)



![]](http://z4.ifrm.com/static/1/pip_r.png)









2:23 AM Jul 14