Re: Unenlagia Pelvis

["Fam Jansma" <fam.jansma@worldonline.nl>]

Jaime Headden wrote:

>Rutger
>
Thank you, thank you, thank you... praise the holiness called HP Jaime
Headden :)
>
>askes about the pelvic structure of the animal (...BIG snip...)
>Articulation is a matter of fitting the bones,
>and I would be tentative regarding the orientation of fragmentary bones,
>but in this case the elements are articulating in a difference of about 3
>degrees _or less_ and do not offer much in the way of retroversion or
>proversion of the pubis compared to the long axis of the ilium. The
>illustration and thus Paul's reconstruction are by far the best idea for
>the pelvis, and it is almost certainly, as in *Rahonavis* and
>*Jewholornis*, mesopubic.
>
But still, the retroversion, even if it just some 3 degrees or something
like that, is not seen in any reconstruction of this element, but it is
there in the material. Second, who says the ilium was that much higher than
that it is preserved? IMHO the dorsal ilium is complete and remarkebly
similair to that of Archaeopteryx as reconstructed by HP Greg Paul in DA. It
might not be completely complete, the area pointing towards the presacral
vertebral column is broken of and is correctly reconstructed in the same
reconstruction. Another point of difference in the preserved material and
the reconstruction is the area just were above the pubis articulates with
the ilium, in the material it follows a sort of circular shape, while it is
reconstructed as being shaped as a half donut. The ischium is also more
reconstructed than that is necessary, I see no reason for the additional
placement of bone and therefore creating the shape that is commonly seen in
the reconstructions.
>
>I cannot see why, on another aside, how Zhang et
>al were able to get away with opisthopuby in their illustration when
>articulation of the ilium and pubis makes for a mesopubic dead-ringer for
>*Rahonavis*, but hey, that's not my bit right now ...
>
The Lord works in mysterious ways, perhaps the Chinese learned the trick
from the Lord ;)
>