Re: Ceratopsian frill size (was Re: DINOSAUR digest 71) (fwd)

[Jeffrey Martz <martz@holly.ColoState.EDU>]

[ The quoted section appears to have been sent only to Jeff.
 Ordinarily I blanch at distributing personal e-mail, but this seems
 harmless enough.  -- MR ]

> remember having read as a kid that the frills of ceratopsians were evolved
> to protect the necks of these animals from attack by animals such as T. Tex
> and his cousins.  Is it possible that the person whom you quoted might
> subscribe to that theory?  Just a thought.  

    If, true, this still has serious discripencies.  _Torosaurus_ of the 
Hell Creek Formation had to deal with Tyrannosaurus rex, and it in fact 
had the longest skull of any land animal ever.  However, _Triceratops_ 
was appaently much more common, and also more common then other 
kinds of large herbivores, including hadrosaurs.  Although it belonged to 
the "long frilled" ceratopsian family, it had one of the shortest frills 
in this group.
     Most of the really big frilled ceratopsians lived a little earlier 
in the late Cretaceous, when smaller tyrannosaurs were around.  However, 
hadrosaurs were (I think) about as common.
     This idea would stem in part on things like preferential prey 
(hadrosaurs or duckbills) of different tyrannosaurs, different defense 
strategies that Triceratops might employ from other ceratopsian species, 
bias in the fossil record...etc.  There is, as far as I can see, no 
perfect, neat correlation between frill, predator size, and the 
likelyhood of a big frilled ceratopsian being the more common and likely 
lrge prey animal, but this is speculation that is hard to talk about 
without more in depth knowledge of Cretaceous ecology.

LN Jeff
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