Re: More from Acta Pal. Pol.

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

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

<More than just the 2 heads of oviraptorid quadrates are birdlike -- could 
someone comment the
other features, about which I know next to nothing? Thanks in advance!>

  clipped from Maryanska and Osmolska's abstract as David clips it:

"(1) two separate facets on the otic process for contacts with the squamosal 
and braincase; (2)
the articular surface for the pterygoid extended to the articular surface of 
the medial mandibular
condyle; (3) the mandibular process provided laterally with a quadratojugal 
process bearing the
quadratojugal cotyla." 

  I have referred to the last feature before on this list. There is a process 
that projects
laterally from the quadrate and sits below the quadratojugal, forming a 
"shelf". In birds, the
lateral process of the quadrate is probably a remnant of the sub-foramen 
portion of the quadrate
body itself, an aproximation of which occurs in dromaeosaur quadrates, more so 
than in
oviraptorids, not as part of the neomorph process seen in oviraptorid 
quadrates. Probably. The
third feature is seen in birds, as well, where the rostral/anterior flange of 
the quadrate, called
the pterygoid flange, has a lamina that extends ventrally towards the cotyla, 
at the mandibular
ramus of the quadrate (where the lower jaw articulates). This is seen in birds, 
as well, but heed:
some birds do _not_ have this feature. It is probably secondary, as basal birds 
possess this, even
*Confuciusornis*. Make no argument about this feature lacking diagnostic value, 
because some birds
lack it. It is a secondary loss in those birds, and therefore irrelevant.


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