Re: How would Tyrannosaurus approach a Triceratops?

[Aidan Karley <aidan_karley@yahoo.co.uk>]

In article <8fb29737b8c8fe9b91a08a2c2ff15146@earthlink.net>, Neal 
Romanek wrote:
> Use the superior eyesight and elevation of the head
>
       Elevation of the head is OK, but the evidence for "superior 
eyesight" in T-rexes (over ceratopsians) is? Increased relative size of 
optical cortices compared between the two species? Could one make an 
assessment of optical acuity from diameter of the eyeball (large 
diameter is necessary to get a large pupil, hence 8m+ telescope 
mirrors, but there's a lot more in a vertebrate eye than just the 
entrance pupil, which could affect acuity in both directions)? In 
modern reptiles (or birds?), how well does the scleral (sp?) ring 
compare with pupil diameter and (our perception of) visual acuity? And 
what about those eagle-eyed eagles with eyeballs much smaller than us 
practically-blind spectacle-wearing humans?
       Thinking more about the physics of eyes (inevitable if you've 
ever read Dawkin's 'Mt. Improbable'), just what sort of focal plane 
acuity variations would one get from having a slit-like pupil, or even 
some of the <strikeout>weirder</strikeout> less symmetrical pupil 
shapes found scattered through the vertebrates? 
-- 
 Aidan Karley,
 Aberdeen, Scotland,
 Location: 57°10' N,  02°09'  W (sub-tropical Aberdeen), 0.021233
 Written at Thu, 18 Aug 2005 09:34 +0100



        
        
                
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