Re: Ceratopian displays (was:Cursorial adaptations)

[Bettyc <Bettyc@flyinggoat.com>]

Chris Campbell wrote:
> That makes sense, and fits with most of the data presented.  However, as
> George points out the frills came before the horns.  I think this can be
> explained, though; if the frills and proto-horns were used for shoving
> matches and defense, the growth of horns can be explained.  We have to
> keep in mind that the horns and frills wouldn't serve only one function;
> the frills might start off as defensive, but then be combined with horns
> for intraspecific competition.  As the horns get longer (possibly in
> response to predation pressures) the intraspecific uses become more and
> more dangerous, so the display functions take over.  The horns remain
> nice and long, though, because they're great as defensive items.
> Meanwhile, those who stuck with nose horns would go on with their
> wrestling and respond to threats with head butts, bites, and short
> charges.  Makes sense, but I dunno how well it'd stand a rigorous
> analysis.

and then came protoceratops whose nose horn is none-existant, has a
greatly reduced frill, and a head that seems to enlarge due to sexual
dimorphism (possibly).   Those beaks still prove to be dang dangerous in
the only species of ceratopians known to use it for defense (IE: the
fighting dinosaurs)


-- 
           Betty Cunningham  
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