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Re: Sauroposeidon




Nick Pharris wrote:

So were basal titanosauriforms all as high-shouldered as _B. altithorax_ and
_G. brancai_, with later titanosaurs re-equalizing their limb lengths?

Here's what I think. _Brachiosaurus_ (and maybe _Giraffatitan_ - and _Euhelopus_ too?) may represent a branch of basal titanosauriforms that became very high-shouldered, due to elongation of the forelimbs (especially the humerus). They also show the anterodorsal inclination of the sacrum associated with this sloping from shoulders to hips. Curiously, this foward and upward "tilting" of the sacral axis is seen in _all_ titanosauriforms, even those (like true titanosaurids) which have approximately equal fore- and hindlimb lengths. This means that their backs must have gently arced from the shoulders to the hips.



Or is
it not entirely certain that both _B._ and _G._ were as high-shouldered as
traditionally depicted?

I think it's OK for _B. altithorax_, but I'm not sure about _Giraffatitan_ or those poorly known Wealden "brachiosaurs" (_Pelorosaurus_ etc).



Tim

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