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Were brachiosaurs really tall at the shoulder? Nick (I think) wrote..
> ...is it not entirely certain that both _B._ and _G._ were as
> high-shouldered as traditionally depicted?
And Tim replied...
> I think it's OK for _B. altithorax_, but I'm not sure about
> _Giraffatitan_ or those poorly known Wealden "brachiosaurs"
> (_Pelorosaurus_ etc).
Rumours have been kicking round for a while that the forelimb-
hindlimb disparity observed in _Brachiosaurus_ species might be (wait
for it) due to the possibly chimaeric nature of the mounts. Most
recently, John Martin and colleagues (1998) assert that all notions
of limb disparity in brachiosaurs result from the Humboldt mount.
Apparently, this is composite reconstruction with some plaster bits.
Janensch (1914, 1929) does not, I believe, give enough measurements
for the disparity to be demonstratable based on the two articulated
specimens of _brancai_ he found.
John et al. conclude provisionally that _brancai_ was higher in front
that behind, but they suggest that _B(?). altithorax_ had front and
hind limbs of equal length. Greg might disagree with this, as in his
_Hunteria_ paper (and in subsequent articles), and as Tim explained
in his email, he has shown how the angle of the sacral verts (called
the anterodorsal inclination by Tim) indicates a thorax that was
held at a raised angle to the ground, rather than parallel to it as
is reconstructed for most dinosaurs (Martinesque archaeopterygids
notwithstanding.... these coelurosaurs clearly mimicked sifakas and
hominines:)). However, if this sacral angle is true for titanosaurs,
maybe the correlation doesn't work. I don't have any titanosaur
figures to hand and don't known enough about sauropods to be
competent. Going back to brachiosaurs (and assuming that they might
be a clade)... WEALDEN TO THE RESCUE! The 'new' Isle of Wight
brachiosaur, still in desperate need of formal publication, does have
forelimb and hindlimb bones preserved. It may therefore reveal the
limb proportions of the animal.
Incidentally, the thing about archaeopterygids mimicking sifakas and
hominines is not something I just made up - Martin actually wrote
this in a recently published article (can't remember which one).
"He who is silent is understood to consent"
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