Re: Corrections Re: Pelvis of *Avimimus*

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

I wrote:

<<Various other animals have a sigmoid curvature of the ilia, including 
dromaeosaurids.>>

David Marjanovic (david.marjanovic@gmx.at) wrote:

<Sorry, of course they have -- in lateral view, while I was writing, apparently 
not clearly
enough, about dorsal view.>

  Oh, I understood that. and that was what my comment was based on. 
*Velociraptor,* for instance,
has an ilium whose dorsal margin is curved sigmoidally in dorsal view (read 
Norell and Makovicky,
1997, AMNovitates). The condition is also apparently present in other 
avian-style "dromaeosaurs"
including *Bambiraptor* and *Sinornithosaurus.*

<<True: the space between the preacetabular alae became narrower dorsally, and 
the space between
the postacetabular alae became wider on the whole height.>>

  1. Inclination of the dorsal margins of the iliac alae sagittally (exaptation 
1: ilia contact
each other over the sacral neural spines, exaptation 2: ilia incline only via 
the preacetabular
alae on either side of the sacral neural spines, not contacting each other).

  2. Iliac postacetabular alae flare laterally more than twice the width of the 
supracetabular
portion of the ilia.

  Also, it would be wise to look at _photos_ of the material, rather than 
illustrations, though
while I do not doubt Paul's skill, he has revised his skeletons, and the new 
data does in fact
change the data from when he published PDW, so this is not a detractment from 
his work. Photos or
more recent illustrations (of which I'm wary of) also tend to _up_ the data 
over the apparent
source of most of your conclusions.

<Just had a look at the *Gallimimus* dorsal view drawing in PDW. It has 
sagitally inclined dorsal
parts of _both_ the pre- and postacetabular alae, and while the postacetabular 
alae do flare
laterally, they don't get parallel again (yet another of my so-far-unspoken 
implications :-( ).
So, just as an example, it doesn't have the combination of characters that 
*Avimimus* and at least
Neornithes have.>

  Well, of course not. Was not my implication. But, you might want to get your 
hands on Osmólska,
Roniewicz, & Barsbold, 1972, in _Pal. Pol._ for a clarification of pelvic 
anatomy in this animal.
Also, Osborn for *Tyrannosaurus*, etc. Primary literature.


=====
Jaime A. Headden

  Aaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhr-gen-ti-na
  Where the Wind Comes Sweeping Down the Pampas!!!!

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