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Uprightedness-data request



ok, it's very late, I'm still at work, and taking a moment or two out to
avoid work.

I am trying to decide for myself how upright all these damn protobirds
were.
I've come across the same sort of thing dino paleontologists come across
when they tried to restore things like hadrosaurs (ie:Iguanodon) first
as quadrapeds (with horned snouts), and then later as a
dragging-the-tail upright creatures (and those handy thumb spikes) and
then later as T-as-in-theropod-shaped bipeds, and then later as
quadrapeds (that can assume bipedal locomotion)...whatever the current
fad is.

We see a flurry of posture changes when a paleotype decides to alter the
orientation of something (as when Ostrom tipped Deinonychus's front end
down to assume the T-shape).  What made Ostrom decide the tipping is
more accurate than what had been assumed before that time?  Atheltic
ability improved in the new position? Or was it something like a
specific clue in the spine and hips?

How does one determine the regular body posture from a rolled up,
stretched out, discombobulated damned dead animal?

I got not just long tails, but the LONGEST TAIL OF ANY THEROPOD on
Seinosauropteryx......I DON'T want to assume he has to be a T-shape
because of that.  I don't want to assume T-shape because of relatives
having T-shapes.  Caudipteryx has a stumpy little tail.....and the same
relatives.

I want some sort of clue in the skeleton as to posture of the animal in
life.  
Where should I be looking in the photograghs in Nat Geo and Nature to
help indicate to me whether Seino was upright or T shaped?  
Hip maybe?  Spine maybe (deformed in the death curl anyways).  The
shoulders don't seem defined enough (most protobirds seem to be
spread-eagled).

Anybody got a comparitive anatomy ref that covers posture clues?

-Betty Cunningham