Re: To Sprawl or Not to Sprawl?...

["Jaime A. Headden" <qilongia@yahoo.com>]

Kris Kripchak (MariusRomanus@aol.com) wrote:

<A few days back, Scott Hartman presented some comments based on his
observations of the microraptors in AMNH Novitate #3381, basically
negating the possibility of the spread-eagle posture. I've begun to wonder
if part of the idea of this sprawling posture was planted in peoples'
minds due to finding basal birds such as *Confuciusornis* preserved with
legs in a sprawled fashion. Is such a posture normal for dead birds? I am
currently under the impression that it is not. Therefore, I'd like to pose
a few questions to the list for those of you who can help me come to terms
with what's actually going on here...>

  This discussion actually occured way back in early 2003 when Greg Paul
presented his observations on *M. gui,* in preparation for the publication
of an article in the _Prehistoric Times_ magazine/fanzine/newsletter:

  http://www.cmnh.org/dinoarch/2003Jan/msg00506.html 

  and the replies are extensive. Scott replied back then too with the same
statement as recently, in reference to the continued portrayal of some of
the art community of spread-legged microraptors:

  http://www.cmnh.org/dinoarch/2003Jan/msg00522.html

<1. Is *Confuciusornis* frequently found preserved in a sprawling pose,
its legs in a spread-eagle fashion like those of *Microraptor*?>

  As in some specimens of *M.* yes, but not in all specimens of
*Confuciusornis.*

<2. If the above is true, is this mode of preservation nothing but a
simple artifact of their burial, in stead of being an indication of the
animal's biomechanics?  Also, if this is just a quirky artifact of their
burial, what is causing this seemingly unique mode of posture
preservation?>

  The prinicple idea that Greg Paul uses to support femoral sprawl was
that because birds were preserved on their backs or bellies, and so was
*Microraptor zhaoianus* and *Sinornithosaurus* sp. (NGMC 91, "Dave"), they
must have had splayed femoral and were wider than deep, contradicting
preservation of *M. gui,* several birds including *Archaeopteryx* and
*Confuciusornis.*

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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


        
                
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