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Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,258 Views)
Wolf Eagle
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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.

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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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Replies:
SpinoInWonderland
The madness has come back...
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Black Ice
Jan 30 2013, 01:58 PM
brolyeuphyfusion
Jan 30 2013, 01:56 PM
Black Ice
Jan 30 2013, 01:52 PM
Quote:
 
Okay, I can do with that, but even if Spinosaurus' spine was made out of playing dough, the outcome woudn't really change by much...

I already said spinosaurus would win this...... Now had you been theropod this would have taken forever to reach the same conclusion.....
I know you already said Spinosaurus would win, I just said that to tell others...and you made it seem as if theropod was a really stubborn guy lol
I'm sure you've seen how he acts when I questioned a muscular ridge lol
Compare his reaction to your more subtle one and you'd see my point.
Lol I see your point, especially when he keeps comparing Carcharodontosaurus' dentition to that of Megalodon :D
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Grey
Kleptoparasite
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brolyeuphyfusion
Jan 30 2013, 01:40 PM
Black Ice
Jan 30 2013, 01:35 PM
Quote:
 
EPIC QUOTE FAIL

rolleyes

Quote:
 
These extensions of the back vertebrae could grow as long as 5.5 feet and the sail like structure that connected the vertebrae are thought to have been thin and skin like.


Why would an animal develop broad spines for a skin-like structure? It would have developed Dimetrodon-esque spines if it had a skin sail, but it didn't....

Spinosaurus just wasn't a sailback...
The spines could be much thicker simply because Spinosaurus is much, much larger than Dimetrodon, structures become thicker when an animal grows up because of ontogenetic changes. A very young Spinosaurus instead would have spines looking more similar to Dimetrodon.

I have nothing against a hump or ridge but it seems this speculation has no significant weight looking at the various modern and recent depictions of Spinosaurus through papers, models and video documentations.
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SpinoInWonderland
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Grey
Jan 30 2013, 02:53 PM
brolyeuphyfusion
Jan 30 2013, 01:40 PM
Black Ice
Jan 30 2013, 01:35 PM
Quote:
 
EPIC QUOTE FAIL

rolleyes

Quote:
 
These extensions of the back vertebrae could grow as long as 5.5 feet and the sail like structure that connected the vertebrae are thought to have been thin and skin like.


Why would an animal develop broad spines for a skin-like structure? It would have developed Dimetrodon-esque spines if it had a skin sail, but it didn't....

Spinosaurus just wasn't a sailback...
The spines could be much thicker simply because Spinosaurus is much, much larger than Dimetrodon, structures become thicker when an animal grows up because of ontogenetic changes. A very young Spinosaurus instead would have spines looking more similar to Dimetrodon.

I have nothing against a hump or ridge but it seems this speculation has no significant weight looking at the various modern and recent depictions of Spinosaurus through papers, models and video documentations.
Saying that a young Spinosaurus has a Dimetrodon-like spine is kinda baseless. It's actually more likely that a young Spinosaurus had no tall spine at all...

Also, Bailey and Stromer suggested a hump, and Scott Hartman believes in a ridge, or a hump(with a sail on top of the hump!)...

Dal Sasso and Cau apparently has no say on the structure on Spinosaurus' back...and the only papers that dealt with Spinosaurus' spine is Bailey's and it gives Spinosaurus a hump...

Models and video documentations are not sources when it comes to the fleshy look of Spinosaurus, they can only be used as references for the basic body design, no Spinosaurus mummy has ever been found.

And here's an 8-meter juvenile, the Spinosaurus at Drouot:
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And here's IPHG 1912:
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Actually, they seem to have the same spine shape...

And the hump/ridge is based on the shape of Spinosaurus' spines...

You must understand that the sail as actually the least likely...
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Bandog
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Everything else is just a dog.
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A hump that is evenly spaced on the back would serve little purpose, same as a muscular ridge. If it were for added strength, there is no reason for it to span the entire back.
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SpinoInWonderland
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Bandog
Jan 30 2013, 05:19 PM
A hump that is evenly spaced on the back would serve little purpose, same as a muscular ridge. If it were for added strength, there is no reason for it to span the entire back.
But it can't be a sail either, the shape of the spines don't look like that of a sailback, an endotherm animal has no use for a thermoregulation structure, and a ridge/hump also serves as display and competitor intimidation...
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Bandog
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Everything else is just a dog.
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brolyeuphyfusion
Jan 30 2013, 05:27 PM
Bandog
Jan 30 2013, 05:19 PM
A hump that is evenly spaced on the back would serve little purpose, same as a muscular ridge. If it were for added strength, there is no reason for it to span the entire back.
But it can't be a sail either, the shape of the spines don't look like that of a sailback, an endotherm animal has no use for a thermoregulation structure, and a ridge/hump also serves as display and competitor intimidation...
It certainly can be a sail, it doesn't seem logical for an animal to waste energy in supporting musculature in a ridge or hump simply for display or intimidation. I doubt it would have problems intimidating competitors if the size estimates are true. I wouldn't be surprised if it has something to do with its semi-aquatic lifestyle.
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SpinoInWonderland
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The spines don't look alike at all Amphicyon...and a muscle attachment would give extra strength to the legs and torso...and the spines on the base of the neck could give extra strength on the neck as well...
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SpinoInWonderland
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Bandog
Jan 30 2013, 05:32 PM
it doesn't seem logical for an animal to waste energy in supporting musculature in a ridge or hump simply for display or intimidation.
It doesn't seem logical for it to grow broad spines just to support a sail, when Dimetrodon-like spines could have done the job...yet Spinosaurus had broad spines...
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Bandog
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I'm not saying it definitley is a sail, just that it isn't a certainty. For some reason, I can't get my head around the idea of an animal that size needing extra strength. The design of the spines don't match up well with any modern animal. No modern animal has attachment spaces that large, they run from the neck to the tail. It doesn't make sense to me.
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SpinoInWonderland
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Bandog
Jan 30 2013, 05:52 PM
For some reason, I can't get my head around the idea of an animal that size needing extra strength.
Why not? It needs the strength to strike fast to catch swimming fish and to help support itself...

Also, the sail is even less likely than a hump or a ridge btw...
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SpinoInWonderland
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Bandog
Jan 30 2013, 05:52 PM
The design of the spines don't match up well with any modern animal.
Yes, that's why it's so uncertain, though they resemble bison spines the most...
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Bandog
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Everything else is just a dog.
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brolyeuphyfusion
Jan 30 2013, 05:57 PM
Bandog
Jan 30 2013, 05:52 PM
The design of the spines don't match up well with any modern animal.
Yes, that's why it's so uncertain, though they resemble bison spines the most...
Agreed except for the length of the animal they span.
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theropod
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I have to correct one point in favour of the sail, as I in fact haven´t seen a single scientist´s reconstruction in which it was evident, all show it in lateral view. They probably don´t do frontal reconstructions for the reason of that meaning they would have to choose one reconstruction for the back. Scientists opinions are not better than ours in this regard and we don´t have many anyway, nothing conclusive from that side and nothing that has a lot of weight.
A sail is not less speculative than a ridge or even a hump.

Obviously adult dimetrodon didn´t develope broad spines either, ontogeny is not a good explanation for such a drastic change in shape. The square cube law might be, but still one would expect a .
Those of Spinosaurus are morphologically in between the bisons´ hump and the Dimetrodons´ sail, so why shouldn´t it be a thinner but muscular structure?
Anteroposteriorly directioned msucles are needed as well, maybe the most in such an extreme biped, the spines didn´t necessarily have to bear strong lateral forces, and if yes, the muscles probably attached near the bottom of the spines, meaning the stress wasn´t necessarily that great.
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Jinfengopteryx
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Aspiring paleontologist, science enthusiast and armchair speculative fiction/evolution writer
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brolyeuphyfusion
Jan 30 2013, 05:37 PM
Bandog
Jan 30 2013, 05:32 PM
it doesn't seem logical for an animal to waste energy in supporting musculature in a ridge or hump simply for display or intimidation.
It doesn't seem logical for it to grow broad spines just to support a sail, when Dimetrodon-like spines could have done the job...yet Spinosaurus had broad spines...
It could have a sail, but not one like in Dimetrodon, with skin spanned in between, rather one like in Planet Dinosaur or the Dinosauria layout. But I think here the definitions can vary. Some may say this is a crest, others believe the structure of the Arizonasaurus in Stuttgart is already a sail.
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SpinoInWonderland
The madness has come back...
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Jinfengopteryx
Jan 31 2013, 12:19 AM
brolyeuphyfusion
Jan 30 2013, 05:37 PM
Bandog
Jan 30 2013, 05:32 PM
it doesn't seem logical for an animal to waste energy in supporting musculature in a ridge or hump simply for display or intimidation.
It doesn't seem logical for it to grow broad spines just to support a sail, when Dimetrodon-like spines could have done the job...yet Spinosaurus had broad spines...
It could have a sail, but not one like in Dimetrodon, with skin spanned in between, rather one like in Planet Dinosaur or the Dinosauria layout. But I think here the definitions can vary. Some may say this is a crest, others believe the structure of the Arizonasaurus in Stuttgart is already a sail.
I wouldn't call the structure it has in Planet Dinosaur a sail, but rather a meaty crest. It's too thick to be a sail
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