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Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,123 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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Jiggly Mimus
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I just don't understand why people underestimate claws... Yes the jaws were more powerful but even today cougars use there claws although there bite does more damage. I am just saying this is an advantage that spino could use.
Cerato help me out. I know that you think claws would help. At least anything the other guy doesn't have is an advantage.
Edited by Jiggly Mimus, Nov 16 2014, 01:30 PM.
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Ceratodromeus
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not entirely sure if its claws would be used in aiding to dispatch rivals, but as a food gathering apparatus? it's feasible.
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Tyrant
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Quote:
 
Quite possible that they did, but that isn't an argument to suggest they were ineffective weapons.


I agree they may have been effective weapons, at least in an ordinary confrontation between predators.

But in a fight to the death? Absolutely not. Their arms are not strong enough to restrain an animal as large as itself so it wouldn't be to effective when grappling. The claws themselves may inflict nasty lacerations, or if its lucky gouge out one of tyrannosaurus's eyes, but it would take a freak circumstance for it to fatally wound a tyrannosaurus with its claws alone.
Quote:
 
I am just saying this is an advantage that spino could use.


And none of us, or at least I assume none of us are denying that. What we are saying is that they aren't a significant advantage.

Edited by Tyrant, Nov 16 2014, 03:21 PM.
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theropod
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Quote:
 
Their arms are not strong enough to restrain an animal as large as itself so it wouldn't be to effective when grappling
Any evidence of that?

Quote:
 
The claws themselves may inflict nasty lacerations, or if its lucky gouge out one of tyrannosaurus's eyes, but it would take a freak circumstance for it to fatally wound a tyrannosaurus with its claws alone.
I’m not sure whether you realize how large these claws are. "Nasty lacerations" is hardly a fitting term for what some 40+cm long claws (that’s without keratin covering) in combination with tremendously strong grasp would do. Depending on where they gripped, certainly they’d have the capacity to piece vital structures. Leaving aside the exact likelyhood, that’d certainly not just be a freak incident.
Edited by theropod, Nov 16 2014, 08:44 PM.
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Jinfengopteryx
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Black Ice
Nov 14 2014, 10:32 AM
258 pages.

Nothing even close to an agreement.

RIP.
To be fair, mostly new posters keep this thread alive. The others realized that this battle depends on the environment.
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Spartan
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theropod
Nov 16 2014, 07:08 PM
40+cm long claws
Its claws were 40cm long? Could you link a source?
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theropod
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Charig & Milner (1997) list the lenght of the first manual ungual of Baryonyx at 31cm. Material of Spinosaurus that was described by Dal Sasso et al. 2005 being about 80% the linear dimensions (although Ibrahim et al. 2014 state 100%, but I think that’s rounded a little liberally) would be expected to have claws 80% longer.
Straight-line lenght in Baryonyx, depending on how you measure it, is 23-24cm based on the aforementioned measurement (Charig & Milner 1997: fig. 35), so Spinosaurus’ manual ungual would be about 41-43cm long in straight line, depending on the exact measurement and without keratin of course.

Conclusion: Spinosaurus likely had claws on its hands that were over 40cm long in straight line, and well over 50cm over the dorsal curve.
I’ve repeatedly made and refined these estimates, and also come up with some figures for the percentage added by the keratin. If you are interested i”d suggest you look up those posts.


References:
Charig, Alan J.; Milner, Angela C.: Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey. Bulletin of the Natural History Museum, London (Geology), Vol. 53 (1997); 1; pp. 11-70
Dal Sasso, Christiano; Maganuco, Simone; Buffetaut, Eric; Mendez, Marco A.: New Information on the Skull of the enigmatic Theropod Spinosaurus, with Remarks on its Size and Affinities. Journal of Vertebrate Paleontology, Vol. 25 (2005); 4; pp. 888-896
Ibrahim, Nizar; Sereno, Paul C.; Dal Sasso, Christiano; Maganuco, Simone; Fabbri, Matteo; Martill, David M.; Zouhri, Samir; Myhrvold, Nathan P.; Iurino, Dawid A.: Semiaquatic Adaptions in a Giant Predatory Dinosaur. Science, Vol. 345 (2014); No. 6204; pp. 1613-1616
Edited by theropod, Nov 17 2014, 04:12 AM.
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Tyrant
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Quote:
 
Any evidence of that?


Not any direct evidence but spinosaurus's arms aren't that big. They are big for a theropod but they still don't appear to powerful for their size. Big cats and bears with proportionally larger and stronger forearms often fail to restrain their prey, so I don't see how spinosaurus would succeed where they have failed.

Quote:
 
I’m not sure whether you realize how large these claws are. "Nasty lacerations" is hardly a fitting term for what some 40+cm long claws (that’s without keratin covering) in combination with tremendously strong grasp would do. Depending on where they gripped, certainly they’d have the capacity to piece vital structures. Leaving aside the exact likelyhood, that’d certainly not just be a freak incident.



Maybe in a prolonged fight they could inflict lethal injuries but I doubt that would happen. Tyrannosaurus's jaws were designed to kill large well defended prey swiftly. In the event of a fight between the two, either tyrannosaurus will either crush spinosaurus's neck or skull, or the spinosaurus would have to quickly incapacitate the tyrannosaurus before it could bite it.
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theropod
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Quote:
 
Not any direct evidence but spinosaurus's arms aren't that big.
That was new to me. In what capacity aren’t they big? I think their size if fairly obvious.

Quote:
 
They are big for a theropod but they still don't appear to powerful for their size.

On Spinosaur forelimb robusticity and strenght:

From Ibrahim et al. (2014):
" The forelimb has hypertrophied deltopectoral and olecranon processes for powerful flexion and extension (Fig. 2A)."

From Charig & Milner (1997): pp.42-45:
"As is typical of theropods, all three major bones [of the forelimb] are short, relative to the general size of the animal; but they are also remarkably robust
and wide, relative to their shortness, with stout shafts and broadly expanded ends
."

"The distance between the upper end of the humerus and the apex
of the deltopectoral crest is approximately 43%
of the entire lengthof the element, while the deltopectoral crest as a whole constitutes
51% of that length
. Between the deltopectoral crest and the internal
tuberosity lies the head of the humerus, a thickened region that
articulated with the glenoid. On the medial surface of the proximal expansion, about half-way between the head and the apex of the
deltopectoral crest, is a distinct ridge some 35 mm in length running along a line that is directed towards the centre point of the shaft. This
ridge, which is clearly present on both humeri, is a rounded hump
distally and tapers proximally to become lower and narrower as it
of pectoral approaches the edge of the bone. To the best of our knowledge, no
coracoid similar structure has been found elsewhere; it may be a prominent
insertion for the pectoralis muscle.
"

"The proximal end [of the ulna] bears an unusually powerful
olecranon
, projecting posteromedially beyond the head of the bone."

Sereno et al. (1998): p. 1299
"Complete pectoral and pelvic bones show a
deep subrectangular acromion on the scapula
and a low obturator flange on the ischium. […] The forearm is
remarkably stout, and manual digit III is robust,
as seen in the size of metacarpal III and the third
ungual
(Fig. 3 and Table 1)."

An indirect mention from Senter & Robins (2005): p. 313:
"They [the forelimbs of A. atokensis] are the stockiest known theropod forelimbs outside
Spinosauroidea
, and their huge muscle scars suggest that
they were heavily muscled and therefore made to be used
in activity involving forces of high magnitude, such as
wrestling with large, violently struggling prey."


They were probably very powerful for their size, and their overall size is very large, both for a theropod and in absolute terms.

Quote:
 
Big cats and bears with proportionally larger and stronger forearms often fail to restrain their prey, so I don't see how spinosaurus would succeed where they have failed.
relative to forelimbs size, it’s unlikely that those of bears or big cats were more powerful than those of Spinosaurus. And they also frequently succeed in restraining their prey, why isn’t that relevant? Also, that includes prey items far larger than themselves.

Quote:
 
Maybe in a prolonged fight they could inflict lethal injuries but I doubt that would happen.
How long do you assume it would take these claws to puncture? Why should that take longer than for T. rex’ teeth do do the same, especially considering the latter are going to encounter far greater resistance due to biting bone? They will puncture, and then they either hit something vital or they don’t. If they do, it’s life threatening, if they don’t, it’s still a virtually inescapable grip.



References:
Charig, Alan J.; Milner, Angela C.: Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey. Bulletin of the Natural History Museum, London (Geology), Vol. 53 (1997); 1; pp. 11-70
Ibrahim, Nizar; Sereno, Paul C.; Dal Sasso, Christiano; Maganuco, Simone; Fabbri, Matteo; Martill, David M.; Zouhri, Samir; Myhrvold, Nathan P.; Iurino, Dawid A.: Semiaquatic Adaptions in a Giant Predatory Dinosaur. Science, Vol. 345 (2014); No. 6204; pp. 1613-1616
Senter, Phil; Robins, James H.: Range of motion in the forelimb of the theropod dinosaur Acrocanthosaurus atokensis, and implications for predatory behaviour. Journal of the Zoological Society of London, Vol. 266 (2005); pp. 307-318
Sereno, Paul C.; Beck, Allison L.; Dutheil, Didier B.; Gado, Boubacar; Larsson, Hans C. E.; Lyon, Gabrielle H.; Marcot, Jonathan D.; Rauhut, Oliver W. M.; Sadleir, Rudyard W.; Sidor, Christian A.; Varricchio, David D.; Wilson, Gregory P.; Wilson, Jeffrey A.: A Long-Snouted Predatory Dinosaur from Africa and the Evolution of Spinosaurids. Science, Vol. 282 (1998); No. 5392; pp. 1298-1302

Edited by theropod, Nov 17 2014, 07:32 AM.
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Bandog
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Theropod, do you think spinosaurus could restrain a similarly sized animal with just its forelimbs/ both forelimbs and jaws?
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Spartan
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theropod
Nov 17 2014, 04:11 AM
Conclusion: Spinosaurus likely had claws on its hands that were over 40cm long in straight line, and well over 50cm over the dorsal curve.
I’ve repeatedly made and refined these estimates, and also come up with some figures for the percentage added by the keratin. If you are interested i”d suggest you look up those posts.


In this case these claws could be more dangerous to T. Rex than I previously thought.
Now the question is how Spinosaurus could use them effectively since it has to get past T-Rex Jaws, doesn't it? Especially when T. Rex has the height advantage.
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Tyrant
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Quote:
 
That was new to me. In what capacity aren’t they big? I think their size if fairly obvious.


Again, if you compare its arms to another theropods, then yes it is. If you were it to most other modern animals, it isn't.

Quote:
 
From Ibrahim et al. (2014):
" The forelimb has hypertrophied deltopectoral and olecranon processes for powerful flexion and extension (Fig. 2A)."

From Charig & Milner (1997): pp.42-45:
"As is typical of theropods, all three major bones [of the forelimb] are short, relative to the general size of the animal; but they are also remarkably robust
and wide, relative to their shortness, with stout shafts and broadly expanded ends."

"The distance between the upper end of the humerus and the apex
of the deltopectoral crest is approximately 43% of the entire lengthof the element, while the deltopectoral crest as a whole constitutes
51% of that length. Between the deltopectoral crest and the internal
tuberosity lies the head of the humerus, a thickened region that
articulated with the glenoid. On the medial surface of the proximal expansion, about half-way between the head and the apex of the
deltopectoral crest, is a distinct ridge some 35 mm in length running along a line that is directed towards the centre point of the shaft. This
ridge, which is clearly present on both humeri, is a rounded hump
distally and tapers proximally to become lower and narrower as it
of pectoral approaches the edge of the bone. To the best of our knowledge, no
coracoid similar structure has been found elsewhere; it may be a prominent
insertion for the pectoralis muscle."

"The proximal end [of the ulna] bears an unusually powerful
olecranon, projecting posteromedially beyond the head of the bone."

Sereno et al. (1998): p. 1299
"Complete pectoral and pelvic bones show a
deep subrectangular acromion on the scapula
and a low obturator flange on the ischium. […] The forearm is
remarkably stout, and manual digit III is robust,
as seen in the size of metacarpal III and the third
ungual (Fig. 3 and Table 1)."

An indirect mention from Senter & Robins (2005): p. 313:
"They [the forelimbs of A. atokensis] are the stockiest known theropod forelimbs outside
Spinosauroidea, and their huge muscle scars suggest that
they were heavily muscled and therefore made to be used
in activity involving forces of high magnitude, such as
wrestling with large, violently struggling prey."


This text sounds impressive, but I could also pull up articles stating how powerful tyrannosaurus's arms were despite their size.

Quote:
 
relative to forelimbs size, it’s unlikely that those of bears or big cats were more powerful than those of Spinosaurus.


Why not? These are animals with proportionality larger animals designed to take down large prey items. Spinosaurus was primarily psicvores that preyed on fish that were a fraction of their size.

Quote:
 
And they also frequently succeed in restraining their prey, why isn’t that relevant?'


Because their prey, while large, were still a fraction of their size.

Quote:
 
Also, that includes prey items far larger than themselves.


Is there any evidence of this? Last I checked the largest thing found in a fossilized spinosaur skeleton was a juvenile iguanodon.

Quote:
 
How long do you assume it would take these claws to puncture? Why should that take longer than for T. rex’ teeth do do the same, especially considering the latter are going to encounter far greater resistance due to biting bone? They will puncture, and then they either hit something vital or they don’t. If they do, it’s life threatening, if they don’t, it’s still a virtually inescapable grip.


We have plenty of modern day accounts of animals quickly killing others similar sized animals through skull and neck bites. We don't have many accounts of animals clawing other similar sized animals to death, and even less of them killing one near-instantly. So far the only animals I know of that have killed animals of similar body sizes to them are cassowaries and giant anteaters, and even then the victims of these attacks were humans, many of which had not anticipated an incoming conflict.
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theropod
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Quote:
 
This text sounds impressive, but I could also pull up articles stating how powerful tyrannosaurus's arms were despite their size.
Sure, I knowvthose texts. But spinosaur forelimbbs are in a whole different league in terms of size. And if you look more closely you'll notice other ways how tyrannosaurid forelimbs are redduced, for example the deltopectoral crest, the olecranon and of course the manus.

I was talking about the modern analogues you claimed to fail frequently when grappling prey. While I think the functional morphology in this case speaks for itself, it should bee pointed out that these also frequently succeed, and that with prey significantly larger thaan themselves. Of course many predators fail more often than they succeed, but that is not restricted to grapplers

Regarding quickly fatal puncture wounds from clawing, you are forgetting about accipitrids.
Edited by theropod, Nov 17 2014, 05:30 PM.
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Jiggly Mimus
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See? Why does everyone underestimate Spino just for size. The claws were obviously strong. I just don't know why people didn't believe me...
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Utahraptor
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Where is it gonna strike with those huge arms and claws? the shins? meanwhile its head is getting chomped. Just by looking at this comparison we can conclude the arms wouldn't have been a difference maker against a big theropod. They were robust because they needed to support its body weight on land and grasp/slash marine life in the water.

Now if it were to be attacked by something like a crocodile then they would be effective defensive weapons because it would be lower to the ground.
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