Re: Refurbished Berlin Brachiosaurus Mount

[Dann Pigdon <dannj@alphalink.com.au>]

Jaime A. Headden writes: 

>   Aside from the shoulder being 6m up, the head is positionable at 9m IN ANY
> DIRECTION from the core of the body, including parallel to the ground. This
> does not require it to be vertical or even semi-vertical. The same is true for
> giraffes, which do not hold their necks vertically (at least passively as
> extensively illustrated and characterized for the bulk of sauropods).

Given the relatively small tail of brachiosaurs, it seems unlikely (from a 
counter-balance perspective) that they walked about with the neck stuck 
straight ahead horizontally. Of course that doesn't necessarily mean an 
extreme vertical S-curve either. It suggests to me that 'normal' (whatever 
that means) neck posture was probably somewhere between straight ahead and 
straight up (assuming straight up was even possible). Maybe representing 
them with necks at a 45 degree angle would be closer to the mark (or at the 
very least represent an 'average' neck posture). 

The elongated forelimbs also suggest a tendancy for the head to reach 
upwards more so than downwards. Long forelimbs in a non-running low-browser 
would seem to be counter-productive (although fast-running low-browsers like 
horses find long forelimbs useful). In fact, I'd expect that a low-browsing 
sauropod would probably have short forelimbs, a low-slung horizontal neck, 
and an impressive tail to counter-balance it. Sort of like a diplodocid 
really. :) 

Everything about the brachiosaur body plan suggests 'high browser' to me. A 
more upright neck and a shorter tail may have allowed them to navigate 
amongst trees better than something like a diplodocid could have. Sticking 
the neck out almost horizontally while moving about would have required 
three-point turns amongst trees, whereas a more upright neck may have 
allowed a much tighter turning circle (ie. if the neck projected forward of 
the forelimbs no farther than the tail projected backward from the 
hindlimbs). 

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Dann Pigdon
GIS / Archaeologist              geo cities.com/dannsdinosaurs
Melbourne, Australia             heretichides.soffiles.com
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