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Spinosaurus aegyptiacus v Tyrannosaurus rex
Topic Started: Jan 7 2012, 02:16 AM (459,199 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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Holtz gives 16m, but without elaborating it. Mortimer cites 17m (mean of Dal Sasso, 2006). Headden gives 1.6-1.8m for the skull but I didn't see any TL estimate from him. I assume that he likely agrees with the rest.

Hartman And Dal Sasso are the two best estimates there are to date, those with the best methodologies (namely scaling of relatives, full body restoration)

Fact is, Cau is the only person who agrees with those estimates (well, and verdugo). All other people who have produced rigorous size estimates for Spinosaurus (I'm saying rigorous because I think we all agree we don't even have to consider estimates such as Therrien & Henderson, 2008, they base on assumptions about scaling of Theropod head/body proportions that are just plain wrong and simplistic) eventually came to conclude it was >15m.
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Vobby
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About Therrien and Henderson, asked Cau what it thought about their study:

Since I hypothesize the skull 1.3 meters long, with the method of Therrien and Henderson is a mass of 7 tonnes. No overshoot of the maximum limit. Obviously, if you use a skull overly large (> 1.5 meters) get colossal masses ... but with a skull the size that I say, the masses are within the theoretical limits.
The study of Therrien and Henderson uses all theropodi exception of shapes with very skulls modified (such as oviraptorosauri). The result is very good, since if you head on articulated specimens are obtained lengths very similar to the real ones. The method is also good for the masses.

And when I asked about Dal Sasso size estimate:


Every time I hear this question (I have lost count), I get a mix of smile and frown. And not because of the question itself of the estimated size, but for the fact that I personally know the two main authors of that article (Cristiano Dal Sasso and Simone Maganuco), and I know in detail the "restroscena" of that study. And I think that this constant mention that estimate does not do justice to their work. As I have said several times to Simon, it's a shame that a nice article that describes in detail the facts relating to a specimen really interesting and unique, a lot of it just to cite a sentence at the end of the final paragraph, the less important and more speculative. In addition, this estimate is quoted incorrectly, out of the context in which it appears.
Here are some excerpts from the last paragraph of Dal Sasso et al. (2005), which faithfully carry:
The section is titled: Hypothetical Skull Size and Body Size [Note the word "hypothetical"].
"Our tentative reconstruction of the skull (Fig. 5B), based on MSNM V4047, UCPC-2 and other spinosaurid specimens (Fig. 5A), Gives a total skull length of about 175 cm." [Notale the word "tentative"].
"As some postcranial elements (ie, the limb bones and the caudal vertebrae)
are hitherto unknown in Spinosaurus, it is difficult to accurately reconstruct its body proportions, I know the real size of MSNM V4047 can only be tentatively hypothesised. "[Note the words" difficult to reconstruct "and" only tentatively hypothesised "]
"With an appropriate degree of caution, the size of the whole animal (Fig. 5C) can be calculated by reconstructing the skeleton on the basis of both the remains of the holotype of Spinosaurus (Stromer, 1915) and Suchomimus (Clear et al. , 1998). MSNM for V4047 The estimated length is about 16-18 m "[note the words" appropriate degree of caution "].
What I mean is that Dal Sasso and Maganuco actually propose that estimate (and Simon knows that I do not agree with, as we have discussed it several times), but, they do so with extreme caution, with great prudence and are keen to point out throughout the text that it is extremely safe and is not intended as a definitive value. I find it gross return only the phrase "16-18 meters" without mentioning the rest of the text, especially the series of assumptions that need to be taken to derive that value (assumptions which, I repeat, I do not share).

http://translate.google.com/translate?u=http%3A//theropoda.blogspot.it/2013/08/miti-e-leggende-post-moderne-sui.html&hl=en&langpair=it|en&tbb=1&ie=UTF-8

About Therrien and Henderson, well, I have no access to the paper, so I can do nothing but trust Cau, at least on the basis on what I know right know.

So, excluding Hartman ( let put off the discussion about him) "the best estimate there is to the data" is the one of Dal Sasso and Manganuco, which don't elaborate it very much and are definetly not sure about it. Cau seems quite sure of himself, at least.
Edited by Vobby, Oct 16 2013, 08:52 AM.
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Verdugo
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Anyway, did you just repeat all the stuff you stated months ago?

Nope, this is still fresh and new 2013, not the all stuffs
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virtually all other rigorous figures agree it was bigger

Again, except from Dal Sasso 18m (which i would demonstrate later), the only 2013 figures having length greater than 14m are those from Scott Hartman
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I think I adressed most of the points Cau made multiple times, not too far back in this thread.

WOW, can you copy your posts to this page ? I don't have time to look through 180 pages to find your post, if you remember where it is, you'll still have better chance finding it than me
Anyway, are you better, smarter than Cau ? If NOT, you have completely NO RIGHT to judge whether the methods are right or not, to address or criticize his methods. If you want to prove that Cau was wrong, then give me other Scientists, Paleontologists's opinions on Cau's methods, not your or any members in this forum opinions and logic.
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There is no proper scientific reason why a 12t biped should be impossible, just guess.

It's no guess...
"To see if Cope's rule really applies to dinosaurs, Hunt and colleagues Richard FitzJohn of the University of British Columbia and Matthew Carrano of the NMNH used dinosaur thigh bones (aka femurs) as proxies for animal size. They then used that femur data in their statistical model to look for two things: directional trends in size over time and whether there were any detectable upper limits for body size.
As for the upper limits to size, the results were sometimes yes, sometimes no. The four-legged sauropods (i.e., long-necked, small-headed herbivores) and ornithopod (i.e., iguanodons, ceratopsids) clades showed no indication of upper limits to how large they could evolve. And indeed, these groups contain the largest land animals that ever lived.
Theropods, which include the famous Tyrannosaurus rex, on the other hand, did show what appears to be an upper limit on body size. This may not be particularly surprising, says Hunt, because theropods were bipedal, and there are physical limits to how massive you can get while still being able to move around on two legs."

The paper from 2012 had already approve Cau's point. If T rex has already reached the limit for bipedal animals, how the hell could Spino get so much bigger/heavier than the limit ?
And BTW, if you think 12+ tonnes is plausible, just give me any scientific stuffs (proofs, evidence, scientist's quotes but not your opinion, logic) that disapprove the 2012 paper that Theropod can still reach pass their upper limit.
If you take a look at Theropod evolution, you can see Cau's point on the limit for bipedal. In Jurassic, no matter how successful Allosauria was, the biggest species Saurophaganax didn't pass the 13m line (probably by a small margin but not as much as Spinosaurus). In the Cretaceous, again Carcharodontosaurid Giganotosarus and Carcharodontosaurus didn't get passed the 13m line either and neither was the Tyrannosaurid T rex. Why couldn't they grow more massive than that ? No matter how successful they were, how dominant they were, why couldn't they pass the 13m line ? Why was Spinosaurus the odd one out ? Was it a quadrupedal or a completely marine animal so that it could grow more massive regardless of the upper limit of bipedal ??
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There are reasons shown by Hartman

Those from Scott Hartman are what i take most consideration. No matter what method he used, it is still the latest estimate for Spinosaurus. But he still haven't estimated the mass, only the length.
Cau's opinion on Hartman estimates, again this Cau's opinion, not mine, i just copy and paste so don't criticize me for this
Andrea Cau
 
DS, from your comment, It Seems you do not understand the main aim of my posts on Spinosaurus size. I'm not interested at all on the actual body size of Spinosaurus, since That value is currently unknown (no moderately complete skeletons are available), I know, any extrapolation is pure speculation and as robust as its skin color. You Mentioned Hartman's skeletal reconstructions: they are very good works, but I would not Consider tham as "actual data": too many assumptions are Necessary when you finish draw a skeleton know from fragmentary remains. Hartman's good artworks can not be Considered in support for any size value blackberries robust than other Estimations. I can not trust any skeletal drawing as a scientific evidence, regardless of its accuracy and the deep competence of its author. Note that other Estimations and reconstructions of the length of the same specimen are between 8.5 and 9.5 meters. Such large size variation for just a single specimen (more complete than any known Spinosaurus) Indicates That there is a very limited scientific support for These claims.
I prefer a different approach, blackberries Rigorous, for example, Henderson's and Hutchinson's papers on theropod sizes. They are the best studies on size variation among big theropods. Nevertheless, I'm not interested on the mere sizes estimated there but on the methods, and the Conclusions: we need a large sample even for rough Estimations as the mere skull-body ration, and, blackberries importantly, allometry matters in a very significant vary. These results mean That in the absence of a good sample, any estimation results meaningless That is so weak, and you can not produce the large size of a taxon by a simple isometry from a smaller relative. All my posts did not want to produce a "true size" alternative to others. They want to show That for any "claim" of giant size, a detailed analysis of the same data may produce them to more conservative, less speculative, and equally valid size estimation. Anyone follows the size he / she prefers: what is important is the scientific evidence supporting That size. In the absence of complete skeletons, I prefer and follow the conservative sizes, Because extraordinary sizes need extraordinary evidence, and the Latter is only from complete (or near complete) skeletons, not fragmentary bones of very poorly known species.

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Dal Sasso

For the Dal Sasso part rolleyes
Andrea Cau
 
Every time I hear this question (I have lost count), I get a mix of smile and frown. And not because of the question itself of the estimated size, but for the fact that I personally know the two main authors of that article (Cristiano Dal Sasso and Simone Maganuco), and I know in detail the "restroscena" of that study. And I think that this constant mention that estimate does not do justice to their work. As I have said several times to Simon, it's a shame that a nice article that describes in detail the facts relating to a specimen really interesting and unique, a lot of it just to cite a sentence at the end of the final paragraph, the less important and more speculative. In addition, this estimate is quoted incorrectly, out of the context in which it appears.
Here are some excerpts from the last paragraph of Dal Sasso et al. (2005), which faithfully carry:
The section is titled: Hypothetical Skull Size and Body Size [Note the word "hypothetical"].
"Our tentative reconstruction of the skull (Fig. 5B), based on MSNM V4047, UCPC-2 and spinosaurid other specimens (Fig. 5A), Gives a total skull length of about 175 cm. " [Notale the word "tentative"].
"As some postcranial elements (ie, the limb bones and the caudal vertebrae)
are hitherto unknown in Spinosaurus, it is difficult to accurately reconstruct its body proportions, I know the real size of MSNM V4047 can be only tentatively hypothesised. " [Note the words "difficult to reconstruct" and "only tentatively hypothesised"]
"With an appropriate degree of caution, the size of the whole animal (Fig. 5C) can be calculated by reconstructing the skeleton on the basis of both the remains of the holotype of Spinosaurus (Stromer, 1915) and Suchomimus (Clear et al., 1998). MSNM for V4047 The estimated length is about 16-18 m "[note the words" appropriate degree of caution. "]
What I mean is that Dal Sasso and Maganuco actually propose that estimate (and Simon knows that I do not agree with, as we have discussed it several times), but they do so with extreme caution, with great prudence, and are keen to emphasize throughout the text that it is extremely safe and is not intended as a definitive value. I find it gross return only the phrase "16-18 meters" without mentioning the rest of the text, especially the series of assumptions that need to be taken to derive that value (assumptions which, I repeat, I do not share).

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Sakamoto didn't make any bite force estimate for Spinosaurus. 2t bases on his own figure for Baryonyx and RELIABLE figures (the skull restorations produced by Scott Hartman, the skull of the NHM Baryonyx, and yes, my own restoration that is in agreement with the others), and it is in full agreement with the askabiologist-answer you posted:

Have he made any bite force for Baryonyx ?? He mentioned completely nothing about that unpublished documents, if you have time, you (or i) should ask him for the validity of that "unpublished document", i'm afraid it's just a load of crap from fanboys.
In the 2013 comments, he stated the same things as he did last year, Spinosaurus bite force was weak

EDIT: I forgot to say something important :P
Theropod
 
And by what logic is an animal no bigger than another animal if the former's subadult has longer vertebrae with bigger centra and much taller neural spines?

The Holotype was in fact, an adult specimen
Andrea Cau
 
"Argue that the holotype specimen described by Stromer was a youth."
It is a myth without foundation.
1 - To determine the stage of growth would need to have the bones to make histological analysis, but unfortunately, the bones are destroyed in 1944.
2 - Normally, you use the suture between the neural arch and center to determine if the animal was ripe or not. If you consult the publication of the 1915 Stromer, we see that the majority of the vertebrae is broken, but that at least one cervical and dorsal retain the suture between the neural arch and center: those two vertebrae show without doubt that the animal was mature. In addition, the sacral vertebrae are fused together centers, another clue that the animal is mature. As you can see, many of those who speak of Spinosaurus do not even know what they're talking, and you probably have never checked the sources, merely talk about things read online and written by who knows who, without a minimum of powers
Edited by Verdugo, Oct 16 2013, 02:24 PM.
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thesporerex
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What did they do ?? I don't like Fragillimus, but getting banned is still a little bit too rough. Especially Black Ice, first Vodmeister get banned now Black Ice, those guys are some of the best members in our forum (and i've never had any conflict with them though :D ).

Fragillimus did this according to taipan:
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He launched an unprovoked personal attack on me, refused to apologise, then responded in email criticising the whole administration of the forum, whilst opening a second account, MightyMaus, and a third account, Glacier. I turned a bit of a blind eye to 'MightyMaus' as there was no IP match and he was behaving himself and allowed him to post here for some time, but then MantisShrimp kept reporting Fragillimus as having a second account.

Black ice got banned for using a second account in april of this year.
Godzillasaurus/godzillaman got banned for spamming this forum with hate speech and what taipan calls his "teenage dramas"
Ursus panthera got banned for idk what
and many people went inactive as I said before but these are some of the most freqent posters of the forum banned

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It seems like a mass extinction since then lol

Yeah alot of people got banned and alot of people went inactive, as I am aware of very few people replaced them. So yeah basically it kinda was a mass extinction but alot of good things came about too.
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BTW, have i met you before ?. Are you a new member or just an old member that change your name ?. If not, nice to meet you :D , if you are a fan of T rex, you will be my best dude ;)

Nah I am fairly new to this forum but I have kinda been here for a while(3 months). And nice to meet you too :D and yes I am a fan of T. rex.
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Verdugo
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Vobby
Oct 16 2013, 01:24 AM
Yes, if you read the last 3 or 4 pages you can read what other members think about Cau's posts. I'm completely with you and Cau, as I posted some page ago. I suppose you are italian too, right?
Edit: I was talking to Verdugo if it's not clear.
Nope, i'm not an Italian, i just use Google Translate to read what Cau's says, but there are many places that i can't understand (well, it is a Google Translate) :P
Anyway, i approve Cau's estimate, because it's just not plausible for me in many ways, but Cau has also demonstrated his method very clear and convincing. While Dal Sasso is mostly speculation, it's not his fault though, because the main aim of his paper is the RICH description of the specimen, not estimating its size. And Hartman doesn't give anything about his method
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blaze
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^You haven't read any of his blogposts then if you think Hartman hasn't said anything about how he recontructed Spinosaurus.

I think the biggest mistake made by Dal Sasso et al was saying 18m, it's ridiculous, I don't see how that is a cautious estimate, I've measured the skeletal in the paper, it's axial lenght is midway between the estimates given, at ~17m but it's only that long because it has a long tail, overall is similar in size to Hartman's 15.6m recontruction which has a tail already 50% of total length IIRC so it's not short tailed by any means.

Edited:
btw one thing that Cau and Hartman certainly agree with is that the holotype is ~40% bigger than Baryonyx, the main difference being that Cau thinks Baryonyx is 9m long while Hartman thinks it's 10m long, we don't know how much of that is due to tail length, maybe the body of Cau's 12m Spinosaurus looks like that of the short tailed 12m Spinosaurus that Hartman made for a Dave Hone's blogpost some time ago, maybe it has a shoter body-neck section than Hartman's or something similar.

Edited by blaze, Oct 16 2013, 09:44 AM.
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Ursus panthera got banned for idk what
Multiple accounts and possibly trolling.
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Vobby
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blaze
Oct 16 2013, 07:43 AM


btw one thing that Cau and Hartman certainly agree with is that the holotype is ~40% bigger than Baryonyx, the main difference being that Cau, whitout having done his own rigorous recontruction thinks Baryonyx is 8m long, while Hartman thinks it's 10m long, we don't know how much of that is due to tail length, maybe the body of Cau's 12m Spinosaurus looks like that of the short tailed 12m Spinosaurus that Hartman made for a Dave Hone's blogpost some time ago.
Cau wrote he takes the estimate of around 9 metres, which is form Charig and Milner (1997).
http://translate.google.com/translate?u=http%3A//theropoda.blogspot.it/2013/08/miti-e-leggende-post-moderne-sui.html&hl=en&langpair=it|en&tbb=1&ie=UTF-8
Edited by Vobby, Oct 16 2013, 08:48 AM.
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oops yes, 9m, my post is only wrong in that part, 12.6m is 1.4 times 9m.
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Spinodontosaurus
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Vobby
Oct 16 2013, 06:33 AM
About Therrien and Henderson, asked Cau what it thought about their study:

Since I hypothesize the skull 1.3 meters long, with the method of Therrien and Henderson is a mass of 7 tonnes. No overshoot of the maximum limit. Obviously, if you use a skull overly large (> 1.5 meters) get colossal masses ... but with a skull the size that I say, the masses are within the theoretical limits.

The problem is that maximum skull length is NOT hugely relevant; I already explained why (using quotes from Scott Hartman) this is the case 2 pages ago.
Cau's 12.6 meter estimate and Hartman's 14 meter estimate share something critical; they are both 40% longer than their respective estimates for Baryonyx. Hartman restores taxa for a living, so his opinion on this carries a lot of weight. It is also noteworthy that Hartman's own Irritator-based skull was 158cm, compared to his actual figure of 165cm, and similarly large ones if one were to scale Baryonyx or Suchomimus to the same rostrum length. >150cm skulls are not "overly large", 130cm skulls are overly small.

Therrien and Henderson... ugh. I can't possibly understand why Cau finds this study to be so reliable... it just isn't. The figures it obtains consistently contradict known fossils elements and the very basis for the calculations - skull length - are frequently miss-cited and are often simply incorrect.

In any case, when one actually uses feasible skull lengths for Spinosaurus, it would still come out as the largest known theropod by Therrien and Henderson's method (and contrary to what they claim, 150cm is not a reasonable Pmx-Qj estimate based on Dal Sass's skull... it is more like 165cm).
Edited by Spinodontosaurus, Oct 16 2013, 01:46 PM.
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Vobby
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Uhm, do you have any scientific article, post or something criticizing Therrien & Henderson? I have no access to their study, but maybe I can understand it bettere reading someone who writes about it.
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theropod
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@vobby: I can send you that paper if you want, but believe me, it´s really flawed.

How can the assumption that ALL theropods are on a single regression (animals as different as Tyrannosaurs, Oviraptorosaurs, Compsognatids and Spinosaurs!), augmented by half of the skull or TL estimates being miscitations and always disagreeing with the actual specimen sizes NOT be flawed?

Cau is very sure of his opinion, we all know. He is TOO sure of it, that´s the problem, and yet he does nothing to support his estimate is in any way better than Dal Sassos, he´s just seeing the rostrum and trying to fit it in a skull as small as possible and then calling it a day and better than what the rest of the scientific community has produced.
That he is so fond of Therrien & Henderson, 2008 is already reason enough to distrust his methodology.

Nobody is saying Dal Sasso´s figure is absolutely sure or anything, but the same problems apply to Cau´s reasoning even more, as well as any other estimate. Cau just doesn´t admit his own work is also just an estimate and not "the truth". The problem is, the latters estimate seems to derive from a premise, that is "Spinosaurus was no bigger than the largest members of other theropod clades", not the premise from the latter´s estimate. It is apparent Cau is always TRYING to get the estimates down as far as possible--because for all other authors they turn out much higher!

Cau is probably right in his scaling of the holotype, since he agrees with Hartman here. What he fails to realise is that it is very unlikely MNSN v4047 isn´t bigger than IPGH (see "The Bite Stuff"). BTW Hartman´s skull for MNSN is 1.8m PMX-SQ, and roughly 1.9m in greatest lenght (including a very long crista protruding posteriorly from the occipitals). The former is what corresponds to the skull lenght from Dal Sasso et al., while 1.65m is PMX-Qj
Edited by theropod, Oct 16 2013, 09:04 PM.
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theropod
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@vobby: here: http://dml.cmnh.org/2007Mar/msg00292.html

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theropod
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Again, except from Dal Sasso 18m (which i would demonstrate later), the only 2013 figures having length greater than 14m are those from Scott Hartman

To put it another way, except for the therrien & Henderson study that is flaweed for lots of different reasons, the only estimate EVER published putting spinosaurus at below 145m is cau´s. Sounds a bit different, doesn´t it?

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WOW, can you copy your posts to this page ? I don't have time to look through 180 pages to find your post, if you remember where it is, you'll still have better chance finding it than me

check the last 2 pages, if you don´t find it I can search. I´m quite busy right now.

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Anyway, are you better, smarter than Cau ? If NOT, you have completely NO RIGHT to judge whether the methods are right or not, to address or criticize his methods.
Soooo, is Cau "better, smarter" than Dal Sasso, his whole team, Hartman, Mortimer, HEadden and Holtz?
How come you think he has the right to judge all of them are completely wrong and just perpetuating children´s myths?
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If you want to prove that Cau was wrong, then give me other Scientists, Paleontologists's opinions on Cau's methods, not your or any members in this forum opinions and logic.
I already did. I already adressd all these points with both the reference to other scientist´s estimates and elaboration why they are so different.

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It's no guess...
it is guess

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As for the upper limits to size, the results were sometimes yes, sometimes no. The four-legged sauropods (i.e., long-necked, small-headed herbivores) and ornithopod (i.e., iguanodons, ceratopsids) clades showed no indication of upper limits to how large they could evolve. And indeed, these groups contain the largest land animals that ever lived.
Congrats, you just quoted a text which included Ceratopsia in Ornithopoda!

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Theropods, which include the famous Tyrannosaurus rex, on the other hand, did show what appears to be an upper limit on body size. This may not be particularly surprising, says Hunt, because theropods were bipedal, and there are physical limits to how massive you can get while still being able to move around on two legs[/color]
Which are not specified on a physical basis, merely presumed statistically for tiny samples of fully terrestrial, distantly related carnosaurs and tyrannosaurs. Not to mention femoral dimensions are not always a good proxy for body size.

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The paper from 2012 had already approve Cau's point. If T rex has already reached the limit for bipedal animals, how the hell could Spino get so much bigger/heavier than the limit ?
Perhaps this is
A. because spinosaurus has a completely different built and lifestyle
B. T. rex is not the limit for bipedal animals, merely the media´s favourite
C. most of the giant theropods used were not the biggest known specimens, eg. Giganotosaurus (FL "135cm" lol ), Carcharodontosaurus (cited FL "126cm" that´s the freaking holotype!), Saurophaganax (the largest individual probably isn´t the ebarer of that femur)

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And BTW, if you think 12+ tonnes is plausible, just give me any scientific stuffs (proofs, evidence, scientist's quotes but not your opinion, logic) that disapprove the 2012 paper that Theropod can still reach pass their upper limit.
First, you give me evidence for the existence of this upper limit (ie. that it is not a result of pathetic sample sizes and data collection bias), best from a pysicist´s viewpoint, and that if it existed it applied to Spinosaurus as well.

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If you take a look at Theropod evolution, you can see Cau's point on the limit for bipedal. In Jurassic, no matter how successful Allosauria was, the biggest species Saurophaganax didn't pass the 13m line (probably by a small margin but not as much as Spinosaurus).
Saurophaganax is known from 4 specimens or so. Yes, that those didn´t pass 13m must mean 13m is the limit for bipedal animals, especially since we have numerous ichnites indicative of greater sizes reached by Jurassic theropods!
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No matter how successful they were, how dominant they were, why couldn't they pass the 13m line ?

The probably could!

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In the Cretaceous, again Carcharodontosaurid Giganotosarus and Carcharodontosaurus didn't get passed the 13m line either and neither was the Tyrannosaurid T rex.
The former two probably did, the latter could have too.

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Those from Scott Hartman are what i take most consideration. No matter what method he used, it is still the latest estimate for Spinosaurus. But he still haven't estimated the mass, only the length.
It should be pretty apparent how Hartmans estimates were made. He made a full-body restoration, which, no matter what excuse Cau finds for it, is miles better than any rough scaling based on hypothetised proportions (whicdh is what the latter is doing)!

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The Holotype was in fact, an adult specimen
I´ll check Stromer´s description again tonight. If that´s right tough, Cau is accusing people like Mortimer of "not even knowing what they are talking"
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Big G
Herbivore
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Terrier & Henderson is a bad study. Now, his Giganotosaurus is almost 14 t with a skull slighty larger than Hartman's one. The Hartman's holotype is 6,8 t with a skull marginally smaller. Doesn't sound a bit weird? Mortimer has criticized this study too.

About the fight...I personally think that this is a 50-50.
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