Giant theropods overview thread

[Grey]

Jul 2, 2013 20:57:06 GMT 5 @brolyeuphyfusion said:

And Cau makes another weird estimate for Spinosaurus, his second since his ~12.5 meter estimate(which he does not go by anymore). A ~1.3-1.4 meter MSNM V4047 skull would be almost all rostrum and little of anything else. Also try putting his proposed ~1.3-1.4 meter long skull onto his very own Spinosaurus reconstruction.

I smell the scent of a wrong method, namely using a coelurosaur to verify a method that tries to extrapolate a megalosauroid's skull...should have used Baryomimus instead...

What about confront Cau directly on his blog with this instead of argue here ?

[theropod]

I don't recall any rigorous neck muscle reconstruction of Acrocanthosaurus atokensis that was done. But what I do know is that spinous processes are an attachment area and their hypertrophy is associated with hypertrophied dorsal neck musculature (eg. transversospinalis cervicis), since this is also done in the case of T. rex as opposed to other tyrannosaurs. So more than with any other theropod I would require evidence for this claim with Acrocanthosaurus (we already have evidence against in other theropods which helps my point). Besides, rigorous myological reconstructions don't actually restore the cervical musculature of Tyrannosaurus that big compared to other theropods, don't let yourself get fooled by some amateur paleoartists who envision it like that.
You may get that impression when you search on google images and compare drawings, but reality is different. Their necks are made for different purposes, and they excell at different things, which makes them difficult to compare. But saying T. rex had the "far stronger neck" is sensationalistic and far too simplified.
If that claim was supported by evidence, we would see it published somewhere.

Have a look at the restoration and descriptions in Snively & Russel, 2007 (and those are at neck lenght parity, while of course Allosaurus has a proportionally much longer neck). Functional Variation of Neck Muscles and Their Relation to Feeding Style in Tyrannosauridae and Other Large Theropod Dinosaurs

All the time these enthusiastic overgeneralisations about neck muscle strenght in theropods...you will realise it is a bit more complicated. Besides, that is a clear case for "the feeding apparata thread", which I made for this exact purpose. I already described it in detail there, feel free to read about it before continuing.


What you see, the robust and proportionally short neck, is because its skull is heavier and it needs a sturdier vertebral collumn in this area. That doesn't automatically mean it is more powerful, and certainly not "tremendously". And reconstructions and visual impression of muscle size are often pretty worthless.

Claims like the ones you are supporting right now don't exist in the peer reviewed literature.

PS: Of course I am talking about parity, that's what the analogy that Holz responded to implied, not that one was stronger in absolute terms despite being smaller (or is a jaguar stronger than a lion in absolute terms, even if we accepted this analogy?).

[stomatopod]

Jul 2, 2013 20:57:06 GMT 5 @brolyeuphyfusion said:

And Cau makes another weird estimate for Spinosaurus, his second since his ~12.5 meter estimate(which he does not go by anymore). A ~1.3-1.4 meter MSNM V4047 skull would be almost all rostrum and little of anything else. Also try putting his proposed ~1.3-1.4 meter long skull onto his very own Spinosaurus reconstruction.

I smell the scent of a wrong method, namely using a coelurosaur to verify a method that tries to extrapolate a megalosauroid's skull...should have used Baryomimus instead...

I fear you do not understand his post and did not read the comments. He did not use Baryonyx beause its skull is too incomplete.

[Grey]

So Thomas Holtz is a moron, for sure.

[Deleted]

You are misunderstanding what I meant. The point is that using unrelated animals would yield weird and potentially outlandish results.

Remember the Therrien and Henderson theropod size paper? That demonstrates my point pretty well.

[Deleted]

Jul 2, 2013 21:04:44 GMT 5 Grey said:

So Thomas Holtz is a moron, for sure.

Nothing I said ever implies that.

EDIT: Oops sorry. That wasn't directed at me.

[Grey]

Jul 2, 2013 21:10:27 GMT 5 theropod said:

he was replying to me, but I won't even bother with it, if you cannot criticise unsourced claims any more. And that from a guy who more than anyone else is of the opinion in many cases people are sensationalistic, including scientists...

You critize absolutely any scientific source or opinion once it does not please you.

Sensationnalistic people ? You're one joke here. The more the time passes, the more I'm conservative (though still liking big things) and I'm relying on cautious works. You have big balls for reproaching me to be sensationnalistic, coming from you, that's epic.

[Grey]

Displacing your quote in the member café thread...


Regarding Holtz quote, I've asked him and I'll get a response about that in the evening. But I have no hope that you'll accept it, being with sources or not.

[theropod]

Jul 2, 2013 21:04:44 GMT 5 Grey said:

So Thomas Holtz is a moron, for sure.

OK. very very funny. I hope you have now satisfied your daily need for fun ridiculing me and we can go on, or better still, you shut up.

And now in all seriousness, if that is what my post makes you think, or how you react to arguments you don't like, you are. You have took it one step too far this time and I hope you realise that.

[creature386]

Jul 2, 2013 21:24:48 GMT 5 theropod said:

You don't like sensationalism, except for in some few animals (T. rex, C. megalodon...)

When was he sensationalistic about Tyrannosaurus? Is he believing into the "larger than Sue" rexes?

[Grey]

Jul 2, 2013 21:43:13 GMT 5 creature386 said:

Jul 2, 2013 21:24:48 GMT 5 theropod said:

You don't like sensationalism, except for in some few animals (T. rex, C. megalodon...)

When was he sensationalistic about Tyrannosaurus? Is he believing into the "larger than Sue" rexes?

Read the post in member café...

[creature386]

I have read it and I have seen that you don't believe in them.

[Deleted]

Jul 2, 2013 22:50:47 GMT 5 creature386 said:

I have read it and I have seen that you don't believe in them.

Nobody with a rational and objective mind would believe in them. Especially UCMP 137538, it wasn't noted with the actual diagnostic characteristics that would place it within Tyrannosaurus, but rather only on size and location.

I would put UCMP 137538 as a "Tyrannosauroidea indet." of unknown size.

[creature386]

Jul 2, 2013 22:55:15 GMT 5 @brolyeuphyfusion said:

I would put UCMP 137538 as a "Tyrannosauroidea indet." of unknown size.

Exactly, that's what the authors did, they only said "large adult" (I believe no one has a problem with it):

Of these sixteen specimens, four represent Tyrannosaurus [Fig. 2]. The first is UCMP 137538, a large (13 cm long) pedal phalanx found in isolation (Fig. 2A). It is identified as a theropod by the gynglymous articular surfaces and deep collateral ligament pits, and is referred to Tyrannosaurus on the basis of its large size, robust construction, and provenance. Comparisons with FMNH PR 2081 [3] show that the bone is a left pedal phalanx IV-2 from a large, adult animal. The proximal end bears four gouges dorsally, and one ventrally, oriented at an oblique angle relative to the axis of the bone. The largest tooth mark is 25 mm long and 7 mm wide.

www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013419#s3

[Deleted]

Jul 2, 2013 23:13:03 GMT 5 creature386 said:

Jul 2, 2013 22:55:15 GMT 5 @brolyeuphyfusion said:

I would put UCMP 137538 as a "Tyrannosauroidea indet." of unknown size.

Exactly, that's what the authors did, they only said "large adult" (I believe no one has a problem with it):

Of these sixteen specimens, four represent Tyrannosaurus [Fig. 2]. The first is UCMP 137538, a large (13 cm long) pedal phalanx found in isolation (Fig. 2A). It is identified as a theropod by the gynglymous articular surfaces and deep collateral ligament pits, and is referred to Tyrannosaurus on the basis of its large size, robust construction, and provenance. Comparisons with FMNH PR 2081 [3] show that the bone is a left pedal phalanx IV-2 from a large, adult animal. The proximal end bears four gouges dorsally, and one ventrally, oriented at an oblique angle relative to the axis of the bone. The largest tooth mark is 25 mm long and 7 mm wide.

www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0013419#s3

Apparently many had problems with the vague size description and began calculating outlandish figures. Even the placement of the toe is uncertain, it seems to be only referred as a IV-2 due to superficial similarities.

The only real diagnostic analysis they did was the one assigning it as a theropod. It could have been a giant alvarezsaur for all we know, but I won't make that leap of faith yet and go with it being an indeterminate tyrannosauroid.