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Re: Parasaurolophus

>Given that sort of a bimodal distribution of morphs in a *single*
>species, the only reasonable conclusion is sexual dimorphism.
>Under those circumstances, it is almost always the male that is
>more gaudy - more display oriented.  Ergo, the large-crested forms
>are males.
>swf@elsegundoca.attgis.com             sarima@netcom.com

Maybe.  But female cassowaries happen to have larger casques than males and
to be larger and more brightly-coloured overall, so we can't claim that we
know for sure what the story was in hadrosaurs.  Admittedly if the crest is
indeed a sound-producing organ (which it certainly is not in cassowaries)
that may, on comparison with living forms, make it more likely that the
larger animals are males, as I can't think offhand of a living tetrapod in
which the female, rather than the male, produces the loudest sounds.
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
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