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Re: New papers (relevant to bird origins)



David Marjanovic wrote-

> Or _C_ and _C_ have reversed this state, or only immature specimens have
> been examined... anyway, the joke is, I haven't seen any of the fossils I
> write of in the paper, I have relied on the primary literature.

Ji et al. (1998) state that the two Caudipteryx specimens described in that
paper were close to maturity at the time of death (neural arches fused to
centra, ossified sternal plates, sternal ribs, etc.).  Not sure about
Confuciusornis.  As for not seeing actual specimens, I can relate.  I'm
stuck in Washington and must rely on the literature for nearly all of my
information.  Good luck on your paper!

> For _Caudipteryx_, however, the best photo I have shows (at 4-fold
> magnification) that the last few caudals look nearly like fused, are quite
> featureless, and the tail tip is quite rounded. The print of this photo is
> too coarse §$&% for more exact statements.
>         How mature is this specimen?

See above for the maturity.  A photo I took of Caudipteryx (NGMC 97-9-A) can
be seen at: http://dinosauricon.com/images/caudipteryx_tail-mm.html .  Note
eighteen vertebrae are preserved and at least one is missing proximally.
Caudipteryx has twenty-two caudal vertebrae, so that leaves three vertebrae
at most not preserved at the tip.  The photo clearly shows that the most
distal vertebrae preserved are not fused.  So even if you don't believe Ji
et al.'s statement that the caudals do not fuse, the pygostyle would be
three vertebrae long at most.

> And I forgot to ask, are any oviraptorosaurian tail ends
> other than those of _Caudipteryx_ and _Nomingia_ known?

Yes.  Ingenia and "Rinchenia" have 27 caudals, while Conchoraptor has 32.
They are all unfused.  I wouldn't trust the generic assignment of
oviraptorid specimens though, as a major revision is underway.

Mickey Mortimer