Re: Ceratopsian frills

["Bjork, Phil" <pbjork@msmailgw.sdsmt.edu>]

Some frills may have caught sounds coming from behind the animal.
 ----------
>From: dinosaur
To: Multiple recipients of list
Subject: Re: Ceratopsian frills
Date: Wed, Feb 8, 1995 1:02PM


To be perfectly frank,  ceratopsian frills meet all the criteria
of a intra-specific display structure.  They are unusually large,
have a large visual cross-section, and are oriented in a position
that would enhance their visibility during face-offs, and they
have the net effect of enlarging the visual profile of the
individual.  In short they fairly shout "Look at me, I am
big and buff".

I am fairly certain that this was their main function.
In this function they were probably brightly colored, at least
in males during the breeding season.  (Like many birds today,
it is possible that they switched to a less gaudy coloration
during the off-season).  However, this is getting into a
rather speculative area, based mostly on extrapolation from
living analogs.

That such display structures existed in dinosaurs is beyond doubt.
>From the crests of hadrosaurs to the snout ridges of many theropods,
there are many examples of structures that cannot be anything else.
[Do you really think those flimsy blades on Dilophosaurus could
possibly have some other function?].

The only issue is whether the crests also functioned in ritual
combat, or even real combat, between competing males.  This
certainly seems likely for forms with solid crests, like
Triceratops, but less likely for the more usual crests with
holes in them.

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.