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Re: Regarding Phytodinosauria, Saurischia, and so forth



In a message dated 95-08-13 15:05:08 EDT, jdharris@lust.isem.smu.edu (Jerry
D. Harris) writes:

> Hey, after all, if such reversals didn't occur, then
>birds wouldn't have such a large digit I either, having been descended from
>reduced-hallux theropods (contra your BCF theory, sorry).
>
>

Umm--just which "reduced-hallux theropods" were these?

BCF states birds STAYED in the trees and did NOT reduce the hallux. What we
call theropods--from ceratosaurs on up--were the ground-dwelling descendants
of these birds. The hallux reduced in EACH group convergently, for the simple
reason that it interfered with cursorial behavior and quickly moved out of
the way. So, for example, I would not find it odd for tetradactyl theropod
tracks to exist--tracks in which the hallux had not yet reduced as much as in
the well-known theropods--but they would be scarce.