Re: Tyrannosaur stance Question

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

Stewart, Dwight wrote:
> 
> I have a question that I have been attempting to get a clear answer on for
> some time.
>    So, here's my question: what features have led to the conclusion that
> Tyrannosaurus rex walked, ran, and (perhaps) primarily stood with its body
> almost horizontal?  Do you agree with this paradigm?  And, if Tyrannosaurus
> rex did move & stand in this posture, COULD he (or she) have stood more
> erect.
> I understand (I think :-)) that the paradigm that birds tend to hold their
> bodies at that angle (some birds, anyway) could open the question up, but
> the physics of the very horizontal stance look awkward to my eyes.  By that,
> I mean that if one takes the hip structure as the fulcrum, then the front
> end of the Tyrannosaurus rex appears to be over-balanced with respect to the
> tail.
> I know the T. rex head had many air pockets and that the small arms would
> also tend to damper this effect.  Nevertheless, the tail doesn't seem quite
> long or robust enough to balance out the structures anterior of the hips.
> Am I missing something here?  

Okay, I'll try to say something remotely scientific here (gasps of
horror). The tail would have been solid bone, muscle, sinew, etc,
whereas the body had lungs and connected air sacks, and various
weight saving features. A model tends to be solid all the way through
(or hollow all the way through, depending on the size I expect).
That said, I too tend to reconstuct a standing Tyrannosaur with a
VERY SLIGHT upward tilt of the body towards the front. Not as extreme
as in birds (which lack counter balancing tails), nor as extreme
as the near-bipedal tail-dragging reconstructions that once abounded.
However when moving, at a brisk walk or at a run (if that was
possible - no that isn't a topic for a new thread, just let it go),
I suspect the body would have levelled out (even blackbirds do
this when they run across a lawn).

> What made me ponder this is that I collect
> 1/40th scale museum quality dinosaur models and the Bataat model was touted
> to me as the most accurate representation of what the T. rex looked and
> stood like.  SO, I bought one and it has this rather nasty habit of doing a
> nose dive when it stands alone.  I asked my friend at the Dinosaur World
> Store about this and he stated; "Gee, they ALL do that."  :-)  My solution
> was to pose my Tyrannosaurus lurking over (propped up) on the back of my
> Triceratops.
> 
> Dwight

Have you ever tried to balance a Barbie doll on its feet (or any
doll for that matter)? Yet we know that humans can stand in a bipedal
fashion. A dead, static model does not have the complex
inner ear arrangement of a living creature (surprise surprise). I
wonder how much luck you would have trying to get a model of a
sleeping flamingo to stand upright on one foot?

-- 
____________________________________________________
        Dann Pigdon
        GIS Archaeologist
        Melbourne, Australia

        Australian Dinosaurs:
        http://www.geocities.com/capecanaveral/4459/
        http://www.alphalink.com.au/~dannj
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