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RE: Brachiosaur flexibility and face-shape (Was: Terra Nova: thoughts)

  With due respect to Mike, it should be noted that if we are only going to 
consider shoulder flexibility in some form of method by which we can determine 
the ability of the animal to decline it's anterior body giraffe-like (as if 
that would be the only way to bed down to drink, ignoring all birds in the 
equation), then we must consider that any potential loss of mobility or bizarre 
range of motion or angle of the shoulder glenoid [not somehow explained through 
taphonomic of biologic deformation] to be offset by the apparent massive blobs 
of cartilage between the upper and lower arm segments and likely in the wrist. 

  Which brings me to an oddity: In _Dinosaur Revolution_, there is a peculiar 
scene where, towards the end of the second episode, a "dinheirosaur" is laying 
down on the ground around the watering hole which forms much of the story's 
focus. This is a juvenile sauropod, although it is inferred for the adult as 
well, that rises up from the laying position by placing its limbs into a flexed 
mammalian posture. The manus is lain against the forearm, and is in turn lain 
against the ground; the palmar surface is not touching the ground; the limb is 
straightened in a typically "large ungulate" way, by the sauropod leaning 
forward, rotating the arm about the shoulder and straightening the leg, and 
bringing the forearm closer to vertical, while the manus remains horizontal. 
This is a process easily observable in goats, horses, camels, giraffes, and 
even elephants. It is likely the basis for the behavior. The animal is able to 
bring its arm into a crooked, "folded" position, enabled in mammals by 
extremely transversely cylindrical limb joints and inflected ends of the 
scapulo-humeral and humero-ulnoradial joints (shoulder and elbow), then reverse 
this by "standing up," then straightening the forelimb.

  While excusing the caveat that these are not mammals, and it being the 
easiest and best known way large quadrupeds "arise" from prone positions 
(horses and other animals that lay on their sides also go through this posture 
once they are prone moving from their recumbent "laying" position), the actual 
morphology of the distal manus/carpus is different in sauropods, and the 
humerus lacks any osseous indications of a cranial inflection. Despite this, 
massive cartilage pads (Schwarz et al., 2007a; Holliday et al., 2010; Bonnan et 
al., 2010) may have formed the necessary amount of tissues to account for large 
rounded knobs to permit the limb to fold adequately.

  So not only should we be wary of shoulder morphology, and the highly 
problematic issue of how much of the humerus is supported by the coracoid 
portion of the scapulocoracoid glenoid, and not the scapula, and thus how much 
an eversion of the glenoid rim actually matters to posture of the humerus in 
the glenoid itself, especially given the absence of known cartilage 
contribution, we should note that range of motion and flexibility of the limb 
are quite literally unknown and possibly unknowable. Moreover, the position of 
the scapula in life may be extremely underestimated, whereas in some the 
scapula lies close to 45 degrees, in others it is nearly vertical (Schwarz et 
al., 2007b), where the mean constant appears to be that the scapula forms the 
entire dorsal rim of the glenoid, and the coracoid only the anterior buttress 
and no part of the weight-supporting region. Modifying the skeleton by Greg 
Paul for the Tendaguru brachiosaur (here: 
 for the relevant posture results in a nearly vertical orientation of the 
scapula, while for *Brachiosaurus antithorax* (here: 
 and derived from the paper Mike mentions below) the scapula would be rendered 
much as is shown, although the coracoid remains not possessing a weight-bearing 
element in regards to the glenoid. The highly tuberculate structure is directly 
alluded to in Schwarz et al., 2007b and Holliday et al., 2010, which should 
indicate a massive amount of cartilage could be present and thus distort the 
actual, "true" shape of the structure, which could very well mean the glenoid 
margin is not, actually, everted.

Bonnan, M. F., Sandrik, J. L., Nishiwaki T., Wilhite, D. R., Elsey, R. M. & 
Vittore, C. 2010. Calcified cartilage shape in archosaur long bones reflects 
overlying joint shape in stress-bearing elements: Implications for nonavian 
dinosaur locomotion. _The Anatomical Record_ 293:2044-2055. 
Holliday, C. M., Ridgely, R. C., Sedlmayr, J. C. & Witmer, L. M. 2010. 
Cartilaginous epiphyses in extant archosaurs and their implications for 
reconstructing limb function in dinosaurs. _PLoS ONE_ 5(9):e13120. 
Schwarz, D., Frey, E. & Meyer, C. A. 2007. Novel reconstruction of the 
orientation of the pectoral girdle in sauropods. _The Anatomical Record_ 
290:32-47. [http://onlinelibrary.wiley.com/doi/10.1002/ar.20405/abstract]
Schwarz, D., Wings, O. & Meyer, C. A. 2007. Super sizing the giants: first 
cartilage preservation at a sauropod limb joint. _Journal of the Geological 
Society of London_ 164:61–65. [ref leads to pdf file: 


  Jaime A. Headden
  The Bite Stuff (site v2)

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 

> Date: Wed, 28 Sep 2011 09:37:59 +0100
> From: mike@indexdata.com
> To: david.marjanovic@gmx.at
> CC: dinosaur@usc.edu
> Subject: Brachiosaur flexibility and face-shape (Was: Terra Nova: thoughts)
> On 27 September 2011 22:27, David Marjanovic <david.marjanovic@gmx.at> wrote:
> >>  That would be one of the few things that Kent and we WOULD agree on.
> >>  Assuming that brachiosaurs drank, they would have needed the ventral
> >>  flexibility to get their heads down to ground level.
> >
> > I assume their shoulder mobility didn't allow the giraffe workaround to this
> > problem?
> Actually, no-one should assume ANYTHING yet about brachiosaur shoulder
> mobility. Although the Giraffatitan paralectotype specimen HMN SII
> preserves a consecutive sequence of vertebral centra through the
> cervicaldorsol transition (C9-D3), all the neural arches are busted
> off, including the zygs, so we can draw absolutely no conclusions
> about neck flexibility in that region. See this helpful composite of
> Janensch's (1950) figures on Kent's site:
> http://ix.cs.uoregon.edu/~kent/paleontology/sauropods/Brachiosaurus/images/cervicodorsalTransition.png
> ... and now I realise you were talking about flexibility of the forelimb, 
> right?
> That's a strange subject. So far as I can see (and I am absolutely no
> expert on appendicular material), there is nothing unusual about the
> forelimbs or shoulder girdles of Giraffatitan. But the coracoid of
> the Brachiosaurus holotype FMNH P25107 has a very strange laterally
> deflected glenoid, discussed briefly in Taylor (2009:796, 802):
> ``One of the most distinctive osteological features of
> Brachiosaurus is the strong lateral deflection of the
> glenoid surface of its coracoid, which in other
> sauropods including Giraffatitan faces directly
> posteroventrally. This may indicate that the humeri
> were also directed somewhat laterally, again in
> contrast to the parasagittally oriented forelimbs of
> other sauropods. Janensch restored the skeleton of
> Giraffatitan with somewhat sprawling upper arms,
> reasoning that "In the forelimb the humerus [...]
> displays characters that are similar to the conditions
> of the humerus of lacertilians, crocodylians and
> Sphenodon, even if pronounced to a lesser degree,
> which, however, show that, in the type of motion of
> the upper arm, a component of lateral splaying was
> included" (Janensch, 1950b:99). Ironically, while it
> is now established that sauropods in general held
> their limbs vertically, it seems possible that
> Giraffatitan's sister taxon Brachiosaurus may have
> been the sole exception to this rule. If correct, this
> would be surprising: the bending stress on a sprawled
> humerus would greatly exceed the compressive stress on
> one held vertically (Alexander, 1985:18), and the
> proportionally slender humeri of Brachiosaurus would
> seem particularly unsuited to such a posture.''
> The best illustration of the coracoid in question is on SV-POW!,
> thanks to photos provided by Phil Mannion:
> http://svpow.wordpress.com/2010/01/25/whats-up-with-the-brachiosaurus-coracoid/
> Finally:
> On 28 September 2011 04:10, Jura <pristichampsus@yahoo.com> wrote:
> > Not mentioned was the weird faces on the brachiosaurs. Aside from the 
> > nostril position choice, they also had duck faces (wide, flat mouths) and 
> > their eyes resulted in the goofiest expressions.
> I've not seen Terra Nova, so they may well have badgered up the faces.
> But the skull of Giraffatitan IS ugly, and the snout is sort of
> flattened. It's best seen in anterior view, but I can't find a
> suitable photo on the Web. (I have one, which I will post on SV-POW!
> at some time, but we have other plans for the next week or two.) In
> the mean time, you can get some idea from anterolateral views, of
> which the best are (get ready for a huge shock) at SV-POW! -- a photo,
> and a figure from Witmer's fleshy-nostrils paper:
> http://svpow.wordpress.com/2008/12/03/shedloads-of-awesome-part-2-mike-and-matts-excellent-adventure/
> -- Mike.