Re: Pinnatus Aenigmaticus

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

David Marjanovic wrote:

<Besides, have you ever looked at the odd shape of the
sternum of A. bavarica? I'd say this is only _one_
sternum (the left or right one) and ought to be turned
around by 90°.>

  This particular bone is concave dorsally with a
saggital craniocaudal depression that correspond to
the foss often preserved above carinae or the fused
sternae; as is present in *Mononykus* and other forms,
as I believe was also described for *Velociraptor* in
Makovicky and Norell, 1999. This suggests that
Wellnhofer's original reconstruction was correct. I
belive there are other corroboratory features, but i
don't have the original paper, just the _JVP_ paper on
the skull. There are also more than just the sternal
features, I believe that are used just to justify a
new species.

<This would explain why there is so much space between
it and the first pair of gastralia in the usual
reconstructions,>

  That is, as I understand it, to qualify the possible
presence of additional cartilaginous extensions of the
sternum, which makes sense from a ontological point of
view.

<and it would probably make the separate species name
A. bavarica unnecessary: A. bavarica was named because
it is smaller than the biggest specimen of A.
lithographica, but exhibited an ossified sternum as a
sign of maturity. An unfused sternum is usually a sign
of immaturity...>

 Ossification of the posterior and lateral processes
in some neornithine birds does not occur until _well_
into ontogeny, often after sexual maturity.

=====
Jaime "James" A. Headden

  Dinosaurs are horrible, terrible creatures! Even the
  fluffy ones, the snuggle-up-at-night-with ones. You think
  they're fun and sweet, but watch out for that stray tail
  spike! Down, gaston, down, boy! No, not on top of Momma!

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