Re: Antorbital fenestra

[Amtoine Grant <ajgrant@eastlink.ca>]

On Friday, November 26, 2004, at 01:39  PM, Andrew A. Farke wrote:

> The antorbital fenestra houses an air sac in all archosaurs. See 
> Witmer 1997
> for *the* paper on the antorbital fenestra. Muscles have little, if 
> anything, to do with the fenestra.

That seemed to be the most logical purpose for me too, I assume for 
communication, as well as display, if not more for display. Since the 
antorbital fenestra in many theropods is the largest opening in the 
skull, I figure that simply being a muscle attachment does not warrant 
the implied danger of giving another theropod such a vulnerable and 
large area to [mortally] wound. On the other hand, housing an air sac 
to be used for visual communication that would bulge out of this 
opening makes more sense. Especially considering that most, if not all, 
theropod skulls are adorned with crests, horns, and ridges of different 
shapes and sizes that in most cases wouldn't make good weapons - 
although they make fantastic inter-specific display devices.
Funny thing is reading about the mating displays of kori bustards is 
what made me ask this question.

> > Kent Caldwell
> >
> > oops - actually, that was my answer. Whenever I think of anorbital 
> > fenestra, I automatically think of the big, modified ones possessed 
> > by theropods; I did not even consider its function in other 
> > archosaurs.

Speaking of modified, has anyone noticed a correlation to the size 
and/or shape of the A/F in theropods in relation to headdress(crests, 
etc.). Also, how has the A/F in theropods changed from pre-theropod 
archosaurs?

Hehe, I love questions.