RE: Sclerotic rings

["Gordon Martin Human" <t_gmhuman@agency.com>]

Mickey Rowe wrote:

> Andrews, K.D. (1996). "An endochondral rather than a dermal origin for
>      scleral ossicles in Cryptodiran turtles", _Journal of Herpetology_,
>      30:257-260.
<snip>
> above claims ossicles in turtles develop by ossification of cartilage
.
.
> Nakamura, K. And Yamaguchi, H. (1991). "Distribution of scleral ossicles
>      in Teleost fishes", _Memoirs of Faculty of Fisheries of Kagoshima
>      University_, 40:1-20.
>
> (Looks at the distribution of ossicles in fish and finds they
> predominate in the eyes of fish like tuna which are large and fast-
> swimming.  Suggests as Al Fraser did that differential pressure across
> the front of the eye required an evolutionary response.

Turtles and tuna? Doesn't this (deformation due to pressure) seem rather
contradictory as an explanation for ossicles, then?

cheers, martin