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Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,133 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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theropod
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Quote:
 
Pneumatization has nothing to do here, you know pneumatization has no relation to bone strength , don't you ??
Pneumatisation does have a relation to bone strenght, although some people may not care for taking the time to understand the complexities.

To claim that pneumatisation had no influence on a structure’s mechanical performance is among the dumbest things I’ve ever read–if that was what you were implying, I sincerely hope I misunderstood you :).

Of course, it’s not as easy as one would like it to be, but at a given diameter a solid rod will be stronger than a hollow tube because there’s more material. At a given amount of material, the hollow tube will be stronger, yes. But this is only one of many factors that greatly complicate the comparison I know you’d love to be so obvious and unambigous.

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I know you're not satisfied so here are the BONUS:
Better, that’s what I was talking about!

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If those are not enough to convince you then i would consider you being ignorant and stop debating here (because you've given me nothing exciting). All you have to defend for your point (Spino being more massive than T-rex) are Paul's statement in a very generic way, lifestyle differences and pneumatization arguments (lifestyle differences and pneumatization arguments have been demonstrated to be invalid by Cau). Seriously, back yourself up with proofs (including publication papers, books, research/quotes from scientists), your pure opinions won't convince anybody
Lol, feeling nostalgic today?
I have already backed up all that I said from scientific sources, but because it’s you I’ll do it again:

The dorsal vertebrae of Spinosaurus are apneumatic and strongly opistocoelous, with greatly enlarged spinous processes forming a deep epaxial structure (Stromer 1915). None of that applies to T. rex (Brochu 2003). Spinosaurus was probably semi-aquatic (Amiot et al. 2010), while T. rex was a fairly cursorial animal for its size (Holtz 2004). Bone diameters or circumferences have given results varying from volumetric estimates for the same specimens to an extreme degree in both relative and absolute terms when applied to two theropods of different clades (Currie & Carpenter 2000 and Bates et al. 2009). And the most basic of all: The morphology of a biological structure adapts to its function, and a difference in this morphology will relate to a difference in function (Hildebrand & Goslow 2001).
The logical and only conclusion to draw from all of this is that the relative weights of T. rex and Spinosaurus can not be deduced from the diameters of their vertebrae.
Enough scientific "proofs" for you, or do you want more? Read them all before you come with that same argument again please!


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No you still misunderstood me ! I'm not here to talk/discuss about f****** Ichthyosaur, Plesiosaur or Gallimimus.
Lol if you are not, then you shouldn”t have posted something about them.
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Here's the link original in Italian, use Google translator or whatever translator that help you understand. I think what Cau pointed out here are pretty clear that i'm not expected to have any discussion about this.
http://theropoda.blogspot.com/2013/12/risposta-ai-lettori-vertebre-di-t-rex.html
You’d really love to put an end to the debate so easily, wouldn’t you?

REFERENCES:
Amiot, Romain; Buffetaut, Eric; Lécuyer, Christophe; Wang, Xu; Boudad, Larbi; Ding, Zhongli; Fourel, François; Hutt, Steven; Martineau, François; Medeiros, Manuel; Mo, Jinyou; Simon, Laurent; Suteethorn, Varavudh; Sweetman, Steven; Tong, Haiyan; Zhang, Fusong; Zhou, Zhonghe: Oxygen isotope evidence for semi-aquatic habits among spinosaurid theropods. Geology, 38 (2010); 2; p. 139-142
Bates, Karl; Manning, Philip; Hodgetts, David; Sellers, William: Estimating Mass Properties of Dinosaurs Using Laser Imaging and 3D Computer Modelling. PLoS ONE, 4 (2009); 2; p. 1-26
Brochu, Christopher: Osteology of Tyrannosaurus rex: Insights from a Nearly Complete Skeleton and High-Resolution Computed Tomographic Analysis of the Skull. Memoir (Society of Vertebrate Paleontology), 7 (2003); p. 1-138
Currie, Philip; Carpenter, Kenneth: A new specimen of Acrocanthosaurus atokensis (Theropoda, Dinosauria) from the Lower Cretaceous Antlers Formation (Lower Cretaceous, Aptian) of Oklahoma, USA. Geodiversitas, 22 (2000); 2; p. 207-246
Holtz, Thomas: Tyrannosauroidea. In: Weishampel, David; Dodson, Peter; Osmólska, Halszka: The Dinosauria. Berkeley (2004); p. 111-136
Hildebrand, Milton; Goslow, George: Analysis of Vertebrate Structure. New York (2001)
Stromer, Ernst: Ergebnisse der Forschungsreisen Prof. E. Stromers in den Wüsten Ägyptens. 11. Wirbeltier-Reste der Baharije-Stufe (unterstes Cenoman). 3. Das Original des Theropoden Spinosaurus aegyptiacus nov. gen., nov. spec.. Abhandlungen der Königlich Bayerischen Akademie der Wissenschaften, Mathematisch-physikalische Klasse, 28 (1915); 3; p. 1-32





Edited by theropod, Sep 9 2014, 07:18 AM.
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theropod
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The Reptile
Sep 9 2014, 06:20 AM
Jinfengopteryx
Sep 8 2014, 02:06 AM
Sorry if this sounds a bit stupid, but I had a discussion with one of the few decent posters on topix who assumed that Spinosaurus could, as a fish-catcher, have an edge in reflexes. What do you think? I believe this is highly speculative because Spinosaurus' fishes were probably not that fast and a technique that consisted of restraining and killing larger ones would be more likely than killing swift ones with a quick bite.<br /><br />P.S. Three words that mean fast in one sentence, nice!
It was undoubtedly capable of striking its jaws down and inward on fish, but that is where it needs to be capable of quickness. Locomotory quickness is just not as necessary for it as it is for other theropods because it would most likely not be chasing down fast-moving prey.
He didn’t write anything about locomotory quickness…
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blaze
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The paper is probably going to be released this Thursday or Friday I think is better to withhold any intense debate about Spinosaurus size (again) until its out and we've had the chance to read it, including Cau's accompanying posts.

Whoever gets it first has to share it with everyone haha.
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Spartan
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theropod
Sep 9 2014, 06:17 AM
Spartan
Sep 9 2014, 02:32 AM
theropod
Sep 8 2014, 11:56 PM
That would make it not significantly heavier than Sue. In this case I would favour the T-Rex.
Err what? It definitely would!
Then I must be misunderstanding you.
If the holotype was 80% of the body mass of Sue (would be 6.4t if Sue was 8t) and the MSNM V4047 specimen was 36% larger than the holotype it would be at 8.7t.
Either we have a different understanding of "significantly heavier"or I'm too dumb for the Math (which is not unlikely given my math skills).
Or did you by "larger" mean its length and not its weight? In that case it would be indeed alot heavier provided your estimations are correct.
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blaze
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He meant 36% larger in linear dimensions yes, this translates to 2.5 times heavier .
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theropod
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Spartan
Sep 9 2014, 09:42 AM
theropod
Sep 9 2014, 06:17 AM
Spartan
Sep 9 2014, 02:32 AM
theropod
Sep 8 2014, 11:56 PM
That would make it not significantly heavier than Sue. In this case I would favour the T-Rex.
Err what? It definitely would!
Then I must be misunderstanding you.
If the holotype was 80% of the body mass of Sue (would be 6.4t if Sue was 8t) and the MSNM V4047 specimen was 36% larger than the holotype it would be at 8.7t.
Either we have a different understanding of "significantly heavier"or I'm too dumb for the Math (which is not unlikely given my math skills).
Or did you by "larger" mean its length and not its weight? In that case it would be indeed alot heavier provided your estimations are correct.
As Blaze wrote, I meant lenght. I’d go with the lower bound for now, it translates to being about 75% more voluminous than FMNH PR 2081 assuming the relative width of the torso from Cau’s post and the shape in lateral view from Hartman’s skeletal minus most of the spinous processes.
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Drift
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Verdugo
Sep 6 2014, 05:21 PM
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I think Caus main point is that Spinosaurus vertebrae do not indicate an aquatic animal, and this is what Verdugo wants to argue, too.

Yes, yes that what i really meant. Thank you MantisShrimp

@Theropod: No you still misunderstood Cau and me. Why is it even so hard for you to understand ?
Yes, we acknowledge that Spino is semi-aquatic and T-rex is cursorial (for its size), those are not what we are discussing about
What Cau really meant is some critics argue that using vertebrate to indicate their size is incorrect because one animal is semi-aquatic while the other is cursorial. The differences in their vertebrate are probably just evolutionary adaptations for their different life style .
And Cau replied to those critics by using Ichthyosaurs and Plesiosaurs as an example for aquatic animals, Gallimimus and Elaphrosaurus as an example for cursorial animals. If Spinosaurus vertebrates were evolutionary adaptations for its aquatic life style, then it's supposed to be short and robust like Ichthyosaurs and Plesiosaurs, instead of being long and slender. Therefore, Spinosaurus vertebrates are NOT evolutionary adaptations for its life style . The same conclusion for T-rex
The Reptile
 
So now people are talking about spinosaurus' vertebrae being evidence of a primarily aquatic lifestyle? Really???

No we aren't. @Theropod just misunderstood
It'd be best to steer clear of the pretentious posts this place has no doubt accumulated,sort of like wading into waste deep raw sewage imo.You proved (to any sane person still undecided) what the outcome would most likely have been as well as discrediting widely accepted misinformation.
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genao87
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I really dont like that low crocodile look they are given to Spino in a news article that I read, seems they are just reading up only on Cau's version of Spino
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blaze
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Where have you been? this isn't Cau's version, the new look comes from Ibrahim et al. (2014) and is possible thanks to a new specimen that preserves the hindlimb, some paleontologists have raised problems with the reconstruction but one thing is clear, short legs are a fact now, how short exactly is what is being disputed.
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genao87
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blaze
Sep 19 2014, 04:43 PM
Where have you been? this isn't Cau's version, the new look comes from Ibrahim et al. (2014) and is possible thanks to a new specimen that preserves the hindlimb, some paleontologists have raised problems with the reconstruction but one thing is clear, short legs are a fact now, how short exactly is what is being disputed.
that is what im disputing, i dont believe Spino is that low to the ground.....it looks like Saurosuchus....


they didnt even bother showing standing up version in the article with the images and video.
Edited by genao87, Sep 19 2014, 11:43 PM.
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The Reptile
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Which is why it has been speculated with a duck or crocodile-like ecology. It was probably far more restricted to hunting water creatures now than it was in the past, as it lacked the same strength capabilities as crocodiles do (which allow them to grab and drown large animals). So while it probably wasn't completely restricted to fish and such, it was probably more-so reliant on them than was proposed in the past due to its new raiusuchian-like stance

As blaze said, the short legs are now a given.
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theropod
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But the "rauisuchian like stance" is not. In fact, it never was. Even with legs the size shown in the paper’s skeletal it was assumed to be a knuckle walker (which, it turns out, requires certain adaptions too).

So regardless of whether it’s a biped or a quadruped there’s nothing rauisuchian-like about it. From nose to toe (quite literally) it’s completely different.
Edited by theropod, Sep 21 2014, 02:04 AM.
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The Reptile
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I wasn't really talking about it moving and standing like postosuchus and such, just that its new general stance is more-so similar to a quadrupedal archosaur than most other theropods
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genao87
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meh, i dont like the look, i kind of still think Spino kinda of look like the way it did when shown on Walking With Dinosaurs. the Spino on that show had short legs as well.

from people who did some digging, they mentioned that the bones/fossils were 27% larger than both reconstructions. it was aquatic but certainly did not look like it was a quadruped.


Edited by genao87, Sep 29 2014, 05:29 AM.
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theropod
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Just that there was no Spinosaurus in Walking with Dinosaurs, and that the authors have posted a rebuttal since. We should look for alternate explanations.
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