Ceratopsian frills

[AnmlPeople@aol.com]

A while back I speculated that Ceratopsian frills,  especially the bigger
ones,  might have acted as huge ear-trumpets,  helping them to ear the
approach of predators.  Tom Holtz shot that one down by arguing that the
frills don't appear to funnel
sound toward the ears.  I've been mulling that over ever since
and am not really convinced:  it would seem to me that the accoustical
properties of the frills would depend on the inner parts,  not just the
externals,  and that the circulatory plumbing some others have mentioned from
time to time could have had a significant amplifying effect.  There's more to
this than just funneling sound to consider;  there's also resonance.  I think
this idea can't be dismissed out-of-hand until and unless there's some way to
test it,  say by beaming sound at a replica and seeing what happens.
 --Merritt Clifton,  editor,  ANIMAL PEOPLE.