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Re: Running dinos
From: firstname.lastname@example.org (Jerry D. Harris)
> Anyway, in the opisthopubic dinosaurs -- the ones in which the
> pelvis was turned backwards (the saurischians, at any rate) -
> a muscle is moved, too! ...
> Since we're on the subject, and before anyone asks, I'm not
> positive if the same holds true for ornithischian dinosaurs.
I am fairly sure it does *not* hold for the ornithischians.
The "opisthopubic" structure in that group originated in a
different manner. Instead of the pre-pubic process rotating
backwards, as in the opisthipubic saurischians, a new process
formed, and the old forward process atrophied. The result would
have been quite different in terms of muscle attachments.
The general belief is that the main reason for the change was to
increase the space available for the guts, since herbivores need
longer intestines and/or extra stomach chambers.
The peace of God be with you.