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Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,095 Views)
Wolf Eagle
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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.

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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).

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Edited by Taipan, Apr 24 2015, 10:10 PM.
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Thalassophoneus
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Spartan
Nov 9 2015, 03:06 AM
Maybe there was a 18m freak Spinosaurus, so what? Then maybe there was also a 14.5m freak T. rex.
Doesn't change anything.
Someone (I think Spinodontosaurus) already explained to you that the 27% longer hindlimbs by Hartman were based on a misunderstanding that has been resolved.
There is UCMP 137538, but the problem is that Spinosaurus is known from neural spines, jaws and several other important parts which are helpfull for all those estimation sthat place it at 15 m. "or more (maybe 18 m.)" whereas UCMP 137538 is only a toe, if I'm not wrong.


Let me make tthis clearer, cause I can see wisecracks coming.

Spinosaurus remains controversial and several estimations place it to 15 m. "or more", with Dal Sasso basically defining "no more" as "18 m."

Tyrannosaurus is known from several specimens and the most complete, and possibly largest one, is Sue which is 12,3 m. long. UCMP 137538 isn't enough proof of the existence of laregst Tyrannosaurus specimens cause it is fragmentary.
Ausar
Nov 9 2015, 04:45 AM
Dunkleosteus Gigas
Nov 9 2015, 12:40 AM
Ausar
Nov 9 2015, 12:23 AM
Also, who in this recent discussion denied that Spinosaurus couldn't use its claws as weapons? Either we didn't necessarily say anything about that or we actually agreed that it could, it's just that we acknowledge that most theropods did not use their forelimbs as their primary weapons.
Spinosaurus could.

Many theropods were using their forelimbs.

Therizinosaurus was adapted to scratching trees and eating small bugs that are inside them. It was doing this with its claws. Actually I believe Therizinosaurus must have been very dangerous at least to those that enraged it.

Troodon is believe to have been adapted to hold things.

Spinosaurus and Baryonyx and other Spinosaurids had sharp claws to hook fish. It is possible they could also use it as weapons.

On the last page of this pdf: http://www.jplegacy.org/downloads/misc/spinosaurus.pdf (is that Ibrahim's original script?) you can see a chart that shows the body length-arm length ratio of different dinosaurs. Allosaurus has the longest forelimbs, in comparison to its body, and I have read several sources suggesting that Allosaurus could use its arms to claw its prey (examples are an encyclopedia that I have and this: http://www.britannica.com/animal/Allosaurus. As you can see the forelimbs of Spinosaurus and Suchomimus are similarly large AND they are known to have been made for fishing. So I assume they could use them as weapons also.
You're arguing against a notion that never argued here. Yes, Spinosaurus definitely used its manual claws as weapons, we get that, no one's saying it didn't. It's just that they don't seem to have been its primary weapons (let alone its primary tools for killing).
Yes, cause between them was its long neck and large head, which was its primary weapon. However this doesn't mean that it couldn't use them on Tyrannsoaurus. It could. Do you get THAT?
Just in case somebody comes here and says "we are talking to you since lots of pages ago, you have made us tired" we are having a conversation and the thread was already over 250 pages long. When it reaches 300 we will celebrate it.
Edited by Thalassophoneus, Nov 9 2015, 05:40 AM.
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Spartan
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I wasn't talking about that toebone, but the possibility (like you were with your "millions of Spinosaurus").
We have absolutely no evidence for any Spinosaurus even approaching 18m.
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Jaws
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@dunk you want to use 18m 10t spino then i will use the 15m 12t phanax either way rexy is larger
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Thalassophoneus
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Spartan
Nov 9 2015, 06:22 AM
I wasn't talking about that toebone, but the possibility (like you were with your "millions of Spinosaurus").
We have absolutely no evidence for any Spinosaurus even approaching 18m.
Yes we have! Dal Sasso's estimate!

If anyone finds a very big Tyrannosaurus skull and estimates the maximum length of Tyrannosaurus at 15 m. then you have every right to say that it could have been up to 15 m. long, cause Sue and several other specimens are close to this length, just like how I have the right to say Spinosaurus might have been up to 18 m. long cause a professional estimated it and several other estimates are clsoe to this length!

Until you find such Tyrannosaurus bone

NO!
Got it?

I SEE YOU THEROPOD!!!!
Edited by Thalassophoneus, Nov 9 2015, 06:37 AM.
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Spartan
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We have also a 20t estimate. So what?
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Jaws
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@dunk you want to use 18m 10t spino then i will use the 15m 12t phanax either way rexy is larger
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Thalassophoneus
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Spartan
Nov 9 2015, 06:38 AM
We have also a 20t estimate. So what?
The 20 ton estimate was from a guy who at the same time estimated its maximum length at 14 m.

Spinosaurus had a significantly lighter structure than other theropods so we don't take it.

Dal Sasso said "around 8 to 9 tons".
No. Spinsoaurus was up to 18 m. and up to 9 tons.
Edited by Thalassophoneus, Nov 9 2015, 06:45 AM.
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Ausar
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Dunkleosteus Gigas
Nov 9 2015, 05:37 AM
Ausar
Nov 9 2015, 04:45 AM
Dunkleosteus Gigas
Nov 9 2015, 12:40 AM

Quoting limited to 3 levels deepSpinosaurushttp://www.jplegacy.org/downloads/misc/spinosaurus.pdf (is that Ibrahim's original script?) you can see a chart that shows the body length-arm length ratio of different dinosaurs. Allosaurus has the longest forelimbs, in comparison to its body, and I have read several sources suggesting that Allosaurus could use its arms to claw its prey (examples are an encyclopedia that I have and this: http://www.britannica.com/animal/Allosaurus. As you can see the forelimbs of Spinosaurus and Suchomimus are similarly large AND they are known to have been made for fishing. So I assume they could use them as weapons also.
You're arguing against a notion that never argued here. Yes, Spinosaurus definitely used its manual claws as weapons, we get that, no one's saying it didn't. It's just that they don't seem to have been its primary weapons (let alone its primary tools for killing).
Yes, cause between them was its long neck and large head, which was its primary weapon. However this doesn't mean that it couldn't use them on Tyrannsoaurus [sic]. It could. Do you get THAT?
YES, I DO GET THAT. I have previously either blatantly implied or explicitly said that I believe Spinosaurus could use its claws as weapons against Tyrannosaurus multiple times. So why do you keep telling me something that I already believe in? Did you read those parts of my comments? Do you have reading issues?
Edited by Ausar, Nov 9 2015, 06:45 AM.
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Thalassophoneus
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I see you there, Spartan.
I hope that things have now become clearer.


Only, Spartan. Was Spinosaurus a quadruped or a biped?
Edited by Thalassophoneus, Nov 9 2015, 06:47 AM.
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Spartan
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Spinodontosaurus
Nov 8 2015, 11:57 PM
An 18 meter Spinosaurus is 20% longer and over 70% more massive than a 15 meter one, so no those two figures are not in any way close in size. And let me state this again - those estimates are based on a specimen that can no longer be considered a specimen of Spinosaurus, the largest specimen is now the holotype specimen which Hartman estimates at 14 meters long and probably weighed less than 7 tonnes.

Clinging to a 10 year old estimate, and only quoting the upper end of that estimate to boot despite further discoveries since then demonstrating those estimates to be inaccurate is precisely the kind of ridiculous thinking that is causing others to call you biased. Trying to use the fact Ibrahim et al. stated "over" 15 meters as some kind of justification for your continued insistence on using the 18 meter estimate is also dishonest, because their reconstruction is not anywhere close to 18 meters long, over curves it is roughly 16 meters but only when scaled to the size of the MSNM V4047 snout that cannot be referred to Spinosaurus.
The Ibrahim et al. model is also chimeric, containing several specimens that are probably not Spinosaurus (or at least are not S. aegyptiacus). This probably has an impact on the length and proportions of various body segments, although the small size of the hindlimbs will not be affected by this.

I need five words to post
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Thalassophoneus
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Spartan
Nov 9 2015, 06:48 AM
Spinodontosaurus
Nov 8 2015, 11:57 PM
An 18 meter Spinosaurus is 20% longer and over 70% more massive than a 15 meter one, so no those two figures are not in any way close in size. And let me state this again - those estimates are based on a specimen that can no longer be considered a specimen of Spinosaurus, the largest specimen is now the holotype specimen which Hartman estimates at 14 meters long and probably weighed less than 7 tonnes.

Clinging to a 10 year old estimate, and only quoting the upper end of that estimate to boot despite further discoveries since then demonstrating those estimates to be inaccurate is precisely the kind of ridiculous thinking that is causing others to call you biased. Trying to use the fact Ibrahim et al. stated "over" 15 meters as some kind of justification for your continued insistence on using the 18 meter estimate is also dishonest, because their reconstruction is not anywhere close to 18 meters long, over curves it is roughly 16 meters but only when scaled to the size of the MSNM V4047 snout that cannot be referred to Spinosaurus.
The Ibrahim et al. model is also chimeric, containing several specimens that are probably not Spinosaurus (or at least are not S. aegyptiacus). This probably has an impact on the length and proportions of various body segments, although the small size of the hindlimbs will not be affected by this.

I need five words to post
Could you provide me some more information about the length of the skull of other Spinosaurids so I might try to calculate the length of Spinosaurus using a 1,5 m. long skull?
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Spartan
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That's not necessary. Spinosaurus is also more lightly built than other Spinosaurids from what I've heard.
Edited by Spartan, Nov 9 2015, 07:08 AM.
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Thalassophoneus
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Spartan
Nov 9 2015, 07:06 AM
That's not necessary. Spinosaurus is also more lightly built than other Spinosaurids from what I've heard.
Yeah, it doesn't matter. I want to do an approximate estimation of the length, assuming that its body structure was similar to that of other Spinosaurids.
Or you could rather do it. You just multiplicate the length of Suchomimus (around 9,5 m. according to Greg Paul) with the number Spinosaurus skull length/Suchomimus skull length. You know how to do it.
Edited by Thalassophoneus, Nov 9 2015, 07:17 AM.
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Spartan
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What's wrong with the estimates by Hartman and Ibrahim et al.?
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Thalassophoneus
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Spartan
Nov 9 2015, 07:28 AM
What's wrong with the estimates by Hartman and Ibrahim et al.?
I want to do my own, even if they are amateur.
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