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Re: Amazing Tendaguru and the most prolific localities in the world
Mike Taylor wrote:
I didn't know it had gone to Korea! Yow. Where did you hear that?
This comes via second-hand information. I'll forward you the name and email
address of the person from whence it came. I don't know if it is the same
specimen you are referring to, but it seems like a daddy of a coincidence
> Firstly, the combination of features seen in the skull is consistent
> with a primitive titanosauriform. I very much doubt that the skull
> belongs to a diplodocoid, or even a basal macronarian.
Remind me, how much material do we have that shows us the differences
between the skulls of basal Macronarians and basal Titanosauriforms?
Well, according to Upchurch et al. (2004) in Dinosauria II, _Bellusaurus_,
_Atlasaurus_ and _Jobaria_ are all basal macronarians, and we have cranial
material for all three (especially _Jobaria_). As for basal
titanosauriforms, the only good skull material I can think of comes from
_Brachiosaurus brancai_ and the putative _Brachiosaurus_ skull from Felch
Not much. From a quick re-skim of Salgado and Calvo 1997, in fact, I
am tempted to say "none at all".
The fossil record has been kind to us since then and offered us _Jobaria_,
which comes with a pretty skull intact.
(Not that I am seriously arguing that Ken's sauropod skull is
_Haplocanthosaurus_, to be clear! All I'm saying that we wouldn't
know _what_ it is were it not for comparisons with _B. brancai_.)
That's true. It shows us that the skull probably comes from a
brachiosaurid; and if it belongs to _B. altithorax_ it would establish that
_brancai_ and _altithorax_ belong in different genera. In other words, it
would 'seal the deal' for the validity of _Giraffatitan_. I agree that,
without the skull, support for splitting the two species into different
genera is weak.
Woah! _What_ longer dorsal column? There is no complete dorsal column of
_either_ _Brachiosaurus_ species in existence. (Well, there are probably a
couple of unpublished ones and no doubt several in the ground :-) The best
_B. altithorax_ dorsal sequence is still that of the type
specimen, consisting of the seven most posterior dorsals in articulation,
and nothing further forward; and the best _B. brancai_ dorsal sequence is
probably that of HMN SII, consisting of D1, D2 and the anterior part of D3,
all lost; plus D4, D7 and a D10/D11 pair --but of course those position
assignments are pretty much guesswork, especially as you get further back.
The HMN SII specimen of _B. brancai_ included an almost complete presacral
vertebral series, according to Heinrich's taphonomic paper (which was based
on Janensch's original field notes). Either the completeness of the
presacral column is exaggerated, or certain vertebrae from HMN SII were lost
or destroyed, and no casts made.