Giant theropods overview thread

[theropod]

?
This applies to all theropods. But fact remains, sue is the largest or at least at the upper end in over 50 specimens.

Average size in a theropod should not be counted as the average for "fully grown" individuals, since this basically means we don´t have any in the majority of cases. It should be counted as the average of mature individuals.

If you make up larger individuals in T. rex, the same has be done with the others even more, so it´s pointless to an epic degree.

[Grey]

It applies to all theropods, of course. Fact remains that according to Holtz, there are chances Sue is most likely an average full grown individual, and not a very large individual by any mean. Sue is a full grown T. rex, no more or less, period. So I laugh even more at the geniuses who spend time to classify individuals in T. rex as a small, an average, a freak... Because despite the sample of T. rex we have, this is still not enough to get an absolutely exact data of the size variations within the species. We merely have an idea.

Sue is not an absolute freak or exceptionnal individual, but anything over Sue size remains pure speculation.

[theropod]

Well, by the same logic specimens like those we have of Giganotosaurus or Spinosaurus very likely aren't even fully grown at all (full grown the way sue is, at a state of " At least one individual (exemplified by FMNH (The Field Museum) PR 2081), showed evidence for prolonged senescence in the form of conspicuously narrow pericortical growth-line spacing ", [Erickson, 2004]), so that's not a surprise.

It is rather exceptional for a mature theropod specimen to be fully grown tough (we've got 2 or so in T. rex, in the quite considerable sample).

Sue is not beyond the size many specimens could have reached. But most specimens never got the chance, and that's the case in all theropods. So this brings us back to just using those individuals considered adults, the result isn't different.

This kind of average is used by scientists, eg. here:

Body mass estimates for Albertosaurus sarcophagus and T. rex taken as mean of all measurements for adult individuals that had reached somatic maturity given in Erickson et al. [34]

We don't have to confine ourselfes to a single specimen just because there's only that single specimen that is that old.

[creature386]

Oct 17, 2013 22:39:13 GMT 5 theropod said:

Well, by the same logic specimens like those we have of Giganotosaurus or Spinosaurus very likely aren't even fully grown, so that's not a surprise.

Do you mean the largest known specimen or to the smaller ones?

[theropod]

Both. Those are small samples. In a sample of 2 random T. rex, the likelyhood to find a 28 year old (~ fully grown) is very low, the same applies to other theropods (evidently Carnosaurs show comparable growth patterns).
It's probable MUCPv-95 is slightly older than MUCPv-95, but if we make such differences, both are likely not fully grown. There is no reason to suspect T. rex' fossil record contains an abnormal amount of non-fully-grown specimens for a theropod.

So in the end, that has no effect on comparative sizes.
If sue is average, carcharodontosaurus/Giganotosaurus/Spinosaurus is below average. <=> If Carcharodontosaurus/Giganotosaurus/Spinosaurus is average, sue is above average.

That depends merely on what samples and criteria you use, but in the end it doesn't make a difference whether we take the sizes shown by the individuals considered adult (I think with most theropods one can be quite confident in the attribution of a specimen to adult or juvenile categories) or just those that have reached the species' maximum age--the latter is just more complicated because it means we have much smaller and more difficult to interpret samples.

[stomatopod]

Well, we do not have any reasearch determining the maturity of Giganotosaurus, and only one specimen which is large enough to determine its size with some certainity (I do not use single bones as a basis for size. If we would have only found isolated bones of Sue, we might have her at nearly at 15 meters if scaled to the holotype. period). The only T. rex comparable to Sue in terms of maturity is Scotty, being a little younger and only a few inches shorter. So I would dare to say that Sue was not exeptional in size. We cannot say anything about Giganotosaurus because we do not have enough material for it. And unless we get a modern Carnegie, which in unlikely, as modern super rich people prefer to hoard the stuff for themselves. Carnegie would have spat in their face for that.

[Grey]

Theropod, this is not because the 30th T. rex to be find appears to be probably an average fully grown that the 30th individual of Giga will be the first average fully grown.
We have no data of the life status in Giga individuals and chances are basically equal.

You suggest that the sample size data of discovered individuals in any species follows the same linear pattern. Which makes no sense.

One advise, try to contact and discuss these matters with a specialist before argue such...speculations.

All what we can say is that in all these theropods we are unlikely to have found the absolute max size there was within the species.

But we can't state anything precise about Giga or Spino based on T. rex.

[theropod]

Firstly, the article you posted mentioned over 50, not 30.

Secondly, chances are highest that a Giganotosaurus, or basically any other specimen in a very small sample, corresponds to the average adult age, not the maximum adult.
Either way, sue represents the maximum size in a large sample of adults, even tough most of these have not reached their absolute upper bound in size.
That, I must repeat, is not speculation.

Still, T. rex specimens from 18 years up are considered adult. There is no reason to suspect an isolated specimen represents an age corresponding to a very rare 28 year old T. rex, that´s the same fallacy as assuming it corresponded to the species´ maximum size. All we can say quite confidently is that FMNH PR 2081, as maximum in a much bigger sample, is also much closer to the maximum size of the species.
And no, that is not the same as claiming that isolated specimen was automatically a small one either, we are talking about average ADULT individual. Using just average and evidently fully grown specimens (such as sue) would be totally pointless since we don´t know that size in 95% of the cases.

What´s called "exceptional" depends on what you compare a taxon to. Sue is exceptional if we compare it to a fossil species with a similar ontogeny but known from only 1 or 2 specimens. Sue is not exceptional when compared to an extant species whose largest known specimens are the largest in thousands.

stomatopod: That's true, but what is more likely, that a given (adult) specimen is sue-fully grown or that it is not? Obviously (considering both in Allosaurus and T. rex that's a very rare occurrence, approximately 4% in the latter's case) that it is not.

So it makes more sense to simply use mature specimens, regardless of individual age, since the latter factor remains an unknown in most of our subjects and nothing indicates age distribution in the animals we can use as templates is in any way unusual.

[Grey]

Sue is not the 50th individual to have been found, that's what I figured.

I don't want to waste my time to read the remaining, that's again your speculated extrapolations. Yes Giga was bigger. Happy ? Have a good day.

Damn, I really can't stand you.

[Fragillimus335]

Oct 18, 2013 17:34:08 GMT 5 Grey said:

Sue is not the 50th individual to have been found, that's what I figured.

I don't want to waste my time to read the remaining, that's again your speculated extrapolations. Yes Giga was bigger. Happy ? Have a good day.

Damn, I really can't stand you.

Grey, you are missing the point. What ever extrapolations of larger size that are applied to Tyrannosaurus in this story must logically be applied to an equal or greater degree for other theropods with smaller sample sizes. Thus you must say that even though both Giganotosaurus and Spinosaurus might be adults, we might find ones 15, 20, or 25% larger than the current largest.

[theropod]

Grey: What I really cannot stand is this dismissive style of posting. Like this, you are really wasting your time.

Sue is the biggest in over 50 T. rex specimens (which is quite interesting considering all the numbers floating around), according to the article you posted yourself. You were all too happy to misinterpret it and then again rant on me because I explained it, but you also happily ignore that part?

[Grey]

You explain nothing, you interpret the case of T. rex to be similar in Giganotosaurus. Your phantasm of a super-Giga.

In both cases, we don't have maximum sized adults, but nowhere you can state that the two gigas are not even full grown. You speculate (AS EVER) based on T. rex. You use T. rex particular status to make up your fantasy monsters. Period.

[theropod]

You don't even get my point and yet you post something like the above...

The probability of finding a full-grown theropod in the sense of "FMNH PR 2081-full grown" is very low, as opposed to finding mature individuals. You see this in T. rex, you do in allosaurus, you do in all theropods with sufficient samples. That's exactly the same case as with average adult sizes, and these two arguments are basically interchangeable.

We don't know the maximum size of T. rex, but we have a much better idea than in Giganotosaurus etc.
We have the ability to come much closer due to simple, basic maths; we have a bigger sample, which will accordingly show a bigger distribution around the mean, ie. the extremes of this sample are much, much closer to the extremes of the whole population than those in a sample of 2.

You also have a much better chance of finding a fully grown(/large) specimen in 50 than you have in 2. That's, I don't know how often I already told you, not the slightest bit of speculation, it's a simple fact.

You see, speculations are what you did, not me. There is absolutely no need to even do that, just compare mature specimens, which increases our samples and the accuracy of comparisons tremendously. What is wrong with that in your opinion?

Of course, it is in disagreement with your personal ideas, about dinosaurs, about me, about yourself...

[Grey]

Better chance, probability...Epic speculation.

Thanks for the psychotherapy in the last line, not only your the ultimate paleontologist but even a psychiatrist...


Yes Giga was bigger than rex. Happy ?

[theropod]

You are the ultimate arrogant, agressive pain in the neck, all the time making some super-smart remarks without knowing what he is actually making them about, so don't tell me what I am!

Do you even know the meaning of the word "probability" or why something is more probable than another thing? No, of course not, because you never spend more than one second reading one of my arguments, if you read it at all.

What is in fact epic speculation is the assumption that a single or one in two individuals represents an age/size class relative to the rest of the population that only constitutes less than 5% in the only related animals we have data on.

You prefer to use such an assumption that is less probable, and call the more probable one a "speculation", of course WITHOUT justification. If you weren't so focused on "badassness" and your preciousssss unfalsifyable assumptions, perhaps you'd have understood me several months or even years ago...

I've really got enough of this, and I don't have to tolerate this kind of behaviour towards me. You do not consider or even read what I write, as you have told me yourself, but you never miss a chance to comment on it with insulting remarks.