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Re: Eagle eyes/ORNITHISCHIAN EYES
Pete Buchholz wrote (3/22/00; 9:17pm):
>I suggest that the reason ornithischians got palpabrals in the first place
so that the eyes wouldn't fall out of their heads-; or more exactly, so that
the eyeballs and eyelids would have ample attachment areas within the eye
socket because the frontals were so thin and narrow side-to-side.<
But Chris Brochu said palpebrals are best developed in robust, blunt-snouted
As he pointed out, they are apparently not homologous with dinosaurian
palpebrals. Apparently their functions were entirely different?
As for another suggestion, I wonder how strong the selection pressure would
be for shading one's eyes against a bright sun?
Perhaps palpebrals are linked to some other character that is/was more
strongly selected for. These suggestions seem almost like "just so" stories
(recalling some discussions on this list from a few years ago).
There seem to be two separate questions here:
1. What good are palpebrals?
2. Why did palpebrals arise?