Giant theropods overview thread

[theropod]

Wow, that's indeed massive. How large it is is impressively demonstrated in "inside natures giants", it seems to fill up nearly the whole body cavity...
So it is not the overall density that had to be reduced, I suspect there are other biomechanical reasons for the evolution of large body size in chondrichthyes but not so much in osteichthyes

[theropod]

I assume this will cause some controversy...

All the reconstructions are based on credible material, mostly Hartmans skeletals (nearly entirely in the cases of acro, T. rex and Giganotosaurus). possible that I exagerated the leg lenght in my Carcharodontosaurus, but the holotypes femur is (better: was) downright gigantic in comparison to its skull size. If anyone wonders why Giganotosaurus is so tall, have a look at which specimen it is (MUCPv-95, NOT CH1, and 95 supposedly has a femur in excess of 150cm). Overall, they all ended up really short, which once more proves how little the axial lenght used for comparison has to do with the lenght of the animal when it was alive.
In case someone wants to measure and check for errors (it is possible that there are ones even tough i did my best), 1cm equals 2px

Not intended to be a factual comparison, but to spark some new toughts and to give an idea...

[Grey]

Yes you assume well.

As often, I feel a mix of admiration for your skill and style at making models and disappointment.

Carcharodontosaurus and Giganotosaurus simply do not outsize Tyrannosaurus in this manner. Except for the upper propositions for Spinosaurus (themselves highly controversial) all the other top three or four simply achieve a similar size.

I can quote Darren Naish :

One thing that Planet Dinosaur seemed big on is the idea that Carcharodontosaurus (and maybe Giganotosaurus) are substantially larger than Tyrannosaurus. I wasn’t a consultant for the series, but I did edit the book, and I requested that they change this whole “bigger than T. rex thing” – these animals were approximately the same size (12-13 m-ish), perhaps with Tyrannosaurus being heavier due to its more robust proportions.
[/b]

Regarding Spinosaurus, David Hone :

So it’s not that I necessarily disagree with a 17 m Spinosaurus (though I think it very likely to be smaller than that) so much as where is the harm in saying “Could be up to 17 m” or “Upper estimates reach 17 m” as opposed to “*was* 17 m”.

blogs.scientificamerican.com/tetrapod-zoology/2011/09/20/vertebrate-palaeontology-at-lyme-regis/

archosaurmusings.wordpress.com/2011/09/22/on-planet-dinosaur/

[theropod]

You see, here they do not outsize it greatly in terms of mass, only in terms of lenght (and height), which, to quote David Hone, Giganotosaurus could and following Sereno, Carcharodontosaurus as well:
archosaurmusings.wordpress.com/2008/11/17/tyrannosaurus-vs-giganotosaurus/
www-news.uchicago.edu/releases/96/960513.dinosaur.shtml
(and yes, I'm aware of the diagram shown, but the height just isn't realistic. The holotype of Giganotosaurus should already be the same height above the hip as sue, MUCPv-95 should be taller)
One scientist or even several being rather cautious doesn't mean these animals were not bigger than T. rex. In fact, they definitely were when compared to the average of T. rex.
The point of this is not to make some assumption and show it, those are just the sizes they end up at. They are not much heavier (still somewhat heavier as commonly acknowledged), and dimensionally a good deal bigger.

As far as Spinosaurus is concerned, here it is not even 15m long, but its bulk at this lenght simply puts other theropods to shame (it is the holotype's approximate proportions which you see in the head and body, but I didn't make the tail longer).

Well, I guess I cannot complain, it was clear from the beginning this would be rather shocking. Still, thanks for the compliments on the artistic side.

[Grey]

Actually, the consensus is that Turannosaurus, Giganotosaurus and Carcharodontosaurus simply achieve similar maximum sizes, with the two carnosaurs potentially outsizing T.rex by length, not so certainly by weight. The first statements when they were both listed as clearly larger than T. rex have no more reason to be, even though only the larger tyrannosaurs specimens rival with those guys.

I'm not particularly fan of cautiousness, but the point is that these animals, if bigger than Rex, are nowhere substantially larger. In your model, they just dwarf it.

The bulky Spino is very speculative too.

But in anycase, this is not the most reliable reconstructions you did.

I remember Holyz considering that one as one of the most reliable, I agree with him :

smg.photobucket.com/user/robban75/media/comparison.jpg.html

[theropod]

Sorry, But I think that comparison is rather bad. I don’t know when and where supposedly Holtz referred to it, but the T. rex is too tall, Spinosaurus not tall enough (at least at the time it was made) and both Spinosaurus and Giganotosaurus are shrinkwrapped (which for some reasons people really like to do as long as it’s to these two).

I guess in that regard we'll have to agree to disagree.
While it is possible they were similar, the giant carcharodontosaurs are indicated to have achieved a greater lenght and likely also a greater weight (which is not consensual but stated by most authorities, for those to whom this matters. Again, the consensus here is cautious because the consensus it the least estimate all can agree about. The vast majority of the literature considers the carcharodontosaurids to have been larger).
That comparison does not reflect what I think, it reflects what the animals end up if scaled to skull lenght. None of them were just made up.
And yes, Giganotosaurus and Carcharodontosaurus are a ton or so heavier in this comparison (not quite as much as you think because they are visually even larger due to their torsos being proportionately deeper and longer), you will be able to find that stated in many, probably most, peer reviewed papers that state an opinion on the matter.

[Grey]

Have you some recent sources listing these animals as significantly bigger than Tyrannosaurus ?

Because Sereno's description is old and quite vague. Also, i respect Sereno but he had a similar reputation to Hurum with the Svalbard, subject to make initial exagerations. sources I've posted are recent. Naish sentence fits perfectly the situation.
These animals does not outsize, nor they clearly outweigh T. rex.
The recent abstract provided by Big Al based on femur length was also in that sense.

The safer approach is that all these giants achieved similar sizes, the only exception being perhaps Spinosaurus.
I cannot personally one paleontologist or paper in currently saying otherwise.

Sorry for the photos, that damn iPhone is a pain in the ass for the links...
tyrannus-rex.proboards.com/index.cgi?board=wwwwww&action=display&thread=102

At worst, tip "Tyrannosaurus Giganotosaurus Spinosaurus" in google images, it's the first pic.

[theropod]

Yeah, now I can see it. I think whoever made that scale was a bit keen on making the other theropods as skinny as possible, it is the typical mainstream scale you can see on the web. But as I said, I don't think MUCPv-95 being not at least a bit taller than sue is viable, based on its leg dimensions. The authors of such scales usually insist in displaying Giganotosaurus merely having a slightly longer tail and skull, which would make up the whole lenght advantage, but that's not true. It was just the dimensionally larger creature for all we know.
T. rex is overestimated slightly in terms of lenght, and the poses are horribly inaccurate (pronated hands, tail and neck posture), so are the body shapes with a good degree of likelyhood (compare to accurate hartman skeletals). I highly doubt a palaeontologist would consider the comparison to have decent accuracy in our century.


I think you yourself have once posted a conversation with Tom Holtz on carnivora where he stated Giganotosaurus, Carcharodontosaurus and Mapusaurus alltogether were likely bigger, but I might be mistaken.
Unfortunately very little has been published in recent years (and nothing concrete), but palaeo-electronica.org/1999_2/gigan/issue2_99.htm has Giganotosaurus at 8t and T. rex at 6t (which probably isn't for sue, only fair considering it's not a comparison of specimens, but of the species).
app.pan.pl/archive/published/app46/app46-193.pdf has Giganotosaurus at 9t, a weight only a single rigorous estimate for the largest T. rex reaches/slightly exceeds.
Mazetta derived a weight figure of 8.2t, saying the holotype estimated at 6.5t was "only marginally smaller than sue", and concluded Giganotosaurus was the largest theropod quite definitively based on this.

You see, scientists have differing opinions, and most are probably wrong, so you can hardly judge me for posting something pointing towards some, just because you have a quote by Naish who considers them comparable-sized.

You see, of course it is absolutely possible that Giganotosaurus did not significantly outsize the largest of 31 T. rexes, but it could be that it actually did. Is is just generally the case that scientists, after the first initial hype, often have a more cautious approach than is realistic. There doesn't seem to be the suggestion of T. rex being the heavier animal, but it is widely accepted that Giganotosaurus and Carcharodontosaurus were longer.

Again, I do not depend on a source for the size, I have made reconstructions based on scientific sources and superimposed the skulls on them (and you know my metodology for the skulls, I guess this is probably the most consistent way there is to make a comparison).


Do you mean the Carrano paper with "recent abstract"? it does not make an analysis of the total lenght, just compare femur and skull lenghts and state a Carcharodontosaurus with equal femur lenght was probably not as heavy as T. rex (keep in mind SGM DIN 1's extrapolated femur lenght is easily 20cm longer than sue's, the same can be said for MUCPV-95, and that this suggestion merely based on femur width). The skulls just happen to be in the dimension carcharodontosaur skulls are relatively short in.

Of course, the safer approach in case you want to avoid overestimating them. However I do also want to avoid underestimating them, something clearly not alien to you when it comes to other animals, and such approaches are not necessarily the most correct. I was not talking about the descrpition, I merely wanted to point out that there are scientific lenght figures for both Giganotosaurus and Carcharodontosaurus that are nearly 2m longer than large T. rex specimens T. rex (and pretty much dwarf smaller ones). You can find the 14m cited quite often for their lenght, in many papers (eg. Moreno et al. 2012) and other sources(eg. Paul 2009), and it has a decent logical basis.

A better phrasing would thus probably be: "there is no consensus of these animals clearly outsizing T. rex, even tough it has been proposed"

But please, let's agree to disagree because we are getting on so well at the moment that I really do not want to get into a long and potentially agressive debate.

[Grey]

The drawing I posted sounds good as it shows the muscular parts and gives a good impression of the overall respective robustness, even though Spino is speculative as ever.
Sorry, but even though nothing certain I favor this over your last with super-high carcharodontosaurs and steroid-Spino !
I've seen many others optimistic propositions of yours, but this is too much for my taste.

There's no latent aggression here don't worry. Simply I state the actual more common consensus expressed here in the scientific community. I'm confident that all giants theropods will eventually achieve similar size, with only possibly tyrannosaurs being perhaps a bit heavier due to more robust proportions. This is also once again suggested more and more when reading discussions on professional blogs.

Sources for the comparative femur length 20 cm longer ?

With this, we simply reach the conclusion, again, that they were just similar in body mass as well.

It is simply pointless (and boring in fact) trying to determine which was the very longer, bigger, higher. We'll don't reach an agreement at now, that's why paleontologists don't work on this question.
That's why I cannot appreciate your model.

[theropod]

You're free to think so, everybody is entitled to their own opinion.

femur lenght:
Giganotosaurus: 137cm*1,08=147cm
Carcharodontosaurus: holotype femur is 126cm, the neotype is very conservatively 20% bigger (conservatively because when I made measurements it actually turned out much larger). This was originally posted by member MysteryMeat at carnivora: COMPARISON(_link))
farm9.staticflickr.com/8079/8289305219_7e6f11e400_o.gif

EDIT:


The neotype is much bigger than the holotype. There might be some slight allometric change in proportions between them, but very likely Carcharodontosaurus is a good deal taller than even the biggest T. rex.

There's no latent aggression here don't worry.

I'm not meaning to start one myself, however you'll certainly understand that this all-too common referral to my "optimistic propositions" resembles it very much.

Simply I state the actual more common consensus expressed here in the scientific community. I'm confident that all giants theropods will eventually achieve similar size, with only possibly tyrannosaurs being perhaps a bit heavier due to more robust proportions. This is also once again suggested more and more when reading discussions on professional blogs.

One doesn't really get the impression that this is the "actual more common consensus". Apart from Naish and Cau, who has ever suggested that?

With this, we simply reach the conclusion, again, that they were just similar in body mass as well.

It is simply pointless (and boring in fact) trying to determine which was the very longer, bigger, higher.

Considering how you tend to insist in suggesting C. megalodon to reach (significantly) larger sizes compared to Livyatan, you expressing this view is quite a double-standard.
Here it actually was the general consensus at the time of this conversation, and actually supported by the evidence (like fact that we have 10-20 times more adult T. rex specimens than for Giganotosaurus or Carcharodontosaurus, while the relative sizes of the largest are at least a close call, if not already tipped in favour of the carcharodontosaurs).

[theropod]

yes, measured the image again. lenght measured from the second to the tenth maxillary alveolus in the neotype is 184px, in the holotype it is 132px
that's a difference of 39%

When scaling the neotype down it becomes apparent the two specimens don't have the exact same maxillary shape, but overall it the difference ends up even greater (for me it ended up at 59% basing on maxillary lenght, but I doubt that's reliable)

[Grey]

All these off-line measurements sound still very hazardous, I cannot have faith in this.
Rest my case until more material or works come to light.
All the three at roughly similar sizes, a possibility for the carnosaurs to reach slightly larger dimensions. None by much.

[elosha11]

Really nice discussion theropod and grey. And very civil too, a welcome change from carnivora. I don't know enough about theropods to really weigh in here, but I will go back and look at the underlying source material when I have time. Great info for anyone who comes to this forum. And great artwork too theropod.

[theropod]

Thanks!

I rest my case too. Anyone not in agreement with it, regard it as potential tough uncertain sizes and keep in mind the lateral view is a slight bias towards the deep tough narrow bodied carnosaurs.

Strange, on carnivora I got a comment saying my spinosaurus looked whale-like...

[creature386]

Mar 28, 2013 17:38:45 GMT 5 Grey said:

I can quote Darren Naish :

One thing that Planet Dinosaur seemed big on is the idea that Carcharodontosaurus (and maybe Giganotosaurus) are substantially larger than Tyrannosaurus. I wasn’t a consultant for the series, but I did edit the book, and I requested that they change this whole “bigger than T. rex thing” – these animals were approximately the same size (12-13 m-ish), perhaps with Tyrannosaurus being heavier due to its more robust proportions.

[/b][/quote]I know that quote, I posted it some times on carnivora. However, it is from a rather cautious point of view. This isn't bad of course, as said, I also used that source (when some people acted like it is a fact that Carchy was bigger than rex), however, it would not exclude the possibility of Carcharodontosaurus being larger than Tyrannosaurus at least in terms of length.

I think the thing what he criticized (and what I do), is this "it was
bigger" story (as done in Planet Dinosaur), rather than stating "it could have been".