Re: sclerotic rings

[Nicholas Roy Longrich <longrich@phoenix.Princeton.EDU>]

On Wed, 22 Feb 1995, Elizabeth Nesbitt wrote:

> Questions: what is the function of sclerotic rings in dinosaurs? 
> Ornithologist consulted had no ideas, except that owls have very large 
> rings, cannot rotate their eyeballs, so rotate their heads instead. They 
> attribute this to carnivory. But the dinos with sclerotic rings are 
> herbivors,and some are large.
> 
> 
        On the subject of eyes, I recall that some birds have a pair of focal 
points (fovea) in the eye, and so are able to set up a binocular system 
with each  eye. This would seem to be a convenient arrangement for the 
predatory dinosaurs, who didn't get around to binocular vision until 
pretty late in their history. More untestability.