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Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,092 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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Mirounga leonina
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Herbivore
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@Dunkleosteus Gigas

What are you trying to prove exactly with your own measurements? What would they offer to the outcome of this battle?
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SpinoInWonderland
The madness has come back...
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T. rex vs S. aegyptiacus: The Ultimate Truth

Andrea Cau
 
Moral winners: Spinosaurus aegyptiacus and Tyrannosaurus rex.
Losers: Homo sapiens (so to speak).

[/thread]
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Thalassophoneus
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Mirounga leonina
Nov 12 2015, 10:39 AM
@Dunkleosteus Gigas

What are you trying to prove exactly with your own measurements? What would they offer to the outcome of this battle?
Nothing. It just came forward.
blaze
Nov 12 2015, 10:26 AM
I forgot to add that, even if that rostrum does turn out to be Spinosaurus, it doesn't mean at all that the 18m giant microcephalic Spinosaurus was a reality.
But it's not microcephalic! I made my own measurements of the length of the full skull of MSNM V4047! It was 173 cm. long! Then I compared it to Baryonyx based on Hartman's reconstruction!
And if MSNM V4047 is the skull upon which all reconstructions are based, like how someone said above, then just how do you know it necessarily belonged to a different genus? I mean couldn't it be that from other specimens of Spinosaurus we found other bones and from that one we found only the skull, which allowed us to have an image of how the skull of Spinosaurus looked like?
blaze
Nov 12 2015, 09:28 AM
@Dunkleosteus Gigas

BSP 1912 VIII 19 from Egypt, incomplete dentary. <-- Only illustrated skull remains from the holotype

MSNM V4047 from Morocco, incomplete rostrum.
UCPC-2 from Morocco, piece of nasals with a crest.
FSAC-KK 11888 From Morocco, cranial bones preserved, pieces of prefrontal, nasals, squamosal, quadratojugal, quadrates, maybe lacrimal and surungular (erroneously referred as "dentary" in text but the figures prove otherwise).
MNHN SAM 124 From Algeria, an even less complete rostrum.
BM231 From Tunisia, an small piece of dentary.
I believe this is enough material to compose an image of the skull of Spinosaurus.
Just deal with it. MSNM V4047 belonged to a Spinosaurus. The skull shape that is attributed to Spinosaurus is
THIS.

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Edited by Thalassophoneus, Nov 13 2015, 02:17 AM.
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blaze
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@Dunkleosteus Gigas
You know what? you are right, it's not microcephalic. Lets analyze your estimates, These are the measurements of Hartman's reconstruction of Baryonyx.

Skull length 95cm
Head-body length 430cm
Total length 940cm

You estimate the complete skull of MSNM V4047 at 173cm, or 1.82 times larger, scaling up we get this.

Head-body length 783cm
Total length 1711cm

How did you get 18m? perhaps you thought Hartman's Baryonyx was 10m? I don't fault you, his older version was 10m but he corrected some scaling issues in his newer version, problem is that the old version also had an skull ~101cm long IIRC so you should have gotten 17.1m anyway, maybe you thought the 95cm skull and 10m total length belonged together? Ignoring that and using the corrected 17.1m based on your methodology, is your estimate larger than Ibrahim et al.'s reconstruction at 16m, Auditore's at 14.6m or Hartman's at 15.6m? the answer is no, the clue is in the head-body length, Ibrahim et al. reconstruction has a head-body length of 8.3m, Auditore's is 8m and Hartman's is 8.2m while yours is only 7.8m.

Ibrahim et al.'s and Auditore's do have a proportionally longer neck though, by 40cm since their skull reconstruction is shorter than yours by ~15cm, torso length is roughly the same. You are effectively arguing over the length of the tail, something that is not going to effect body mass beyond some tens of kg.
Edited by blaze, Nov 13 2015, 06:11 AM.
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Thalassophoneus
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Blaze

Quote:
 
How did you get 18m? perhaps you thought Hartman's Baryonyx was 10m? I don't fault you, his older version was 10m but he corrected some scaling issues in his newer version, problem is that the old version also had an skull ~101cm long IIRC so you should have gotten 17.1m anyway, maybe you thought the 95cm skull and 10m total length belonged together?


No such thing happened. I got 17,2 m., I think, and I supported Dal Sasso's 16-18 m. claim exactly because not only I fell within the estimates and very clsoe to the upper one but also because several other estimates place Spinosaurus at over 15 m.

I have said this like 100 times. I base the 18 m. estimates on
my estimates
other estimates that fall at over 15 m.

Quote:
 
You are effectively arguing over the length of the tail, something that is not going to effect body mass beyond some tens of kg.


I'm arguing over the animal's overall length, even though I don't think it won't really affect the battle. Its maximum weight must have been around 10 tons on the 18 m. estimation and less for the 15 or 14 m. estimations.
And at this point I would like to bring back our previous debate about MSNM V4047.

Who told you that the fact that this skull was found in an area, with bones that might have belonged to different spinosaurids, means that it might not have belonged to a Spinosaurus? What if Evers doesn't mention this skull cause he accepts it as a Spinsoaurus fossil but says that other local fossils might not have belonged to Spinosaurus?
Edited by Thalassophoneus, Nov 13 2015, 05:43 AM.
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FishFossil
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(sigh)....


The lure of debate is strong.

Here.

https://qilong.wordpress.com/2015/10/20/pale-spinos-sigilmassasaurus/

He basically takes the word out of my mouth as to why we can't just attribute all spinosaurid remains to S. aegypticus.
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Spartan
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In this thread we have learned that "over 15m" is the same as "18m".
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Mirounga leonina
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Dunkleosteus Gigas
Nov 13 2015, 05:40 AM
I'm arguing over the animal's overall length, even though I don't think it won't really affect the battle.
Then I personally don't see the point then.
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Thalassophoneus
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Spartan
Nov 13 2015, 05:53 AM
In this thread we have learned that "over 15m" is the same as "18m".
Not the same! Similar. Close. We argue about which is closer to the maximum size of Spinosaurus. We are dinosaur lovers. It's our job.
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Spartan
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Tyrannosaurus was over 12m long, so it was 14.8m. Where is my paycheck?
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Thalassophoneus
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FishFossil
Nov 13 2015, 05:52 AM
(sigh)....


The lure of debate is strong.

Here.

https://qilong.wordpress.com/2015/10/20/pale-spinos-sigilmassasaurus/

He basically takes the word out of my mouth as to why we can't just attribute all spinosaurid remains to S. aegypticus.
Quote:
 
(specimens that don’t share overlapping elements with other specimens; and secondarily because they are “associated” after the fact, much as MSNM V4047 was deemed more or less the correct snout for the FSAC-KK 11888 Ibrahim et al. specimen)


I noticed specifically this part cause we are arguing mostly about this specific specimen. Does this mean that MSNM V4047 shouldn't be attributed to Spinosaurus Aegyptiacus? What if FSAC-KK 11888 should rather be attributed to another species?

That's what I have said since long ago. The fact that this rostrum was found in an area with lots of bones that might have belonged to different species doesn't mean that it shouldn't be attributed to Spinosaurus.
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blaze
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I forgot to add this to my previous reply, I think it address your last paragraph.

Quote:
 
And if MSNM V4047 is the skull upon which all reconstructions are based, like how someone said above, then just how do you know it necessarily belonged to a different genus? I mean couldn't it be that from other specimens of Spinosaurus we found other bones and from that one we found only the skull, which allowed us to have an image of how the skull of Spinosaurus looked like?
For about 50 years, all reconstructions of Apatosaurus used an skull based on Camarasaurus therefore that has to be the correct skull, that is your argument. We don't say we know that MSNM V4047 necessarily belonged to a different genus, it could be all the skull bones we've found do belong to Spinosaurus but we don't know if that's the case and we have no way to discern to what spinosaurid those bones belong to, that is our argument, the only one talking as if he knows for sure the identity of those bones is you.

Quote:
 
I believe this is enough material to compose an image of the skull of Spinosaurus.
Again, since we don't have a way to discriminate to what taxon those bones belonged to what you are getting by combining them all is the image of a generalized spinosaurine, you can use the shape of such composite skull to represent the head of Spinosaurus but you can't use specific measurements.

Now about the overall length, this is where you get it wrong, overall length only affects mass when you are comparing the same thing but due to the different relative tail length of the different reconstructions out there you are not comparing the same thing, cut the tail and compare only head-body length.

Dal Sasso et al. (2005) 8.2m
Ibrahim et al. (2015) 8.3m
Auditore (2014) 8m
Hartman (2013) 8.2m
Yours 7.8m

If Ibrahim et al. say that their reconstruction suggest an animal around 6-7 tonnes, how can you say that your methodology indicates 10 tonnes when it results in an animal at most, only as big as Ibhraim et al's?
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Thalassophoneus
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Spartan
Nov 13 2015, 06:06 AM
Tyrannosaurus was over 12m long, so it was 14.8m. Where is my paycheck?
You state this. You have to support this.

Do you know any tyrannosaurid bone that might have belonged to Tyrannosaurus and would give an estimated length of 14,8 m.? You do? What is it? A toe! Interesting!

Cause we also have a skull that is believed to have belonged to a Spinosaurus and that might have measured up to 173 cm. long and this would give a length of over 17 m. if we scale with Baryonyx.

Got the difference, smartass?
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Spartan
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Maybe Spinosaurus wasn't the only one who could afford a tailjob?
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blaze
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lol, that's funnier when you consider that before we got decent tail remains of Tyrannosaurus, mounted skeletons based on specimens now seen as 12m long were 15m because they were given very long tails.
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