Re: Eagle eyes

["Jordan Mallon" <j_mallon@hotmail.com>]

David Krentz wrote:

>  Perhaps palpebrals reduced glare from the sun, sort of a sun visor to 
> keep the
> animal from being sun-blind while grazing etc.  Maybe for raptors it aided 
> in
>  focusing on prey down on the ground below.

This same idea came up on the List a couple years ago ('98, I think) in a 
thread I had entitled "Theropod Sunglasses?"  I had suggested that maybe the 
theropod brow ridges and hornlets were useful for shielding the eyes from 
the sun.  During that discussion, someone (sorry, I forget who) brought up 
the idea that some ornithischians posessed palpebrals that may have served 
the same purpose.  It may be helpful to search the archives for information 
on this subject.  Personally, I think it's an interesting propostion as many 
birds (as has already been mentioned) and even the sidewinder snake use 
these adaptions to cut down on glare from the sun.

-Jordan Mallon
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