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> Right. Under special circumstances of territory or resource deprivation (for
> example), dwarf forms will evolve. What special circumstances were there over
> the entire planet that caused Cope's Rule to be systematically violated
> during the entire length of the Jurassic Period? Of course Cope's Rule is no
> rule--just a guide--but when it is broken, it is usually for interesting and
> unusual reasons. I'm willing to listen to anything. And I'm not talking about
> the random variations in size you will always find among the species in
> taxonomic groups, each of which probably has a very specific, individual
> cause.

       Is Cope's Rule the one that says big animals generally eveolve 
from small ones, not the other way around?  I beleive that one of the 
exceptions to this rule has to do with dwarfism in animals that become 
genetically isolated on islands.  A nice example is the kiwi, a tiny 
ratite that is supposed to have evolved from a larger ancestor, as 
suggested by its humungous egg.  Hate to get back to speculation, but a 
large theropod that became isolated on, say, the Solnhofen islands might
get down to Archaeopteryx size.   
      I'm still of the opinions that the arboreal origin of birds is no more 
likely than the crusorial theory.  SImple, plausible sounding theories 
founded on no more fossil evidence than their competetors are to be 
approached carefully. If one was to speculate about how a flying animal 
might delevelop wings, lengthening the fingers and stretching 
skin like a bat or pterosaaur SOUNDS more plausible that 
elaborating these funny, complex little scale derivitives 
into aerodynamic structures.  However, in the case of birds, 
thats not what happened.                      
     By the way, I think the whole bird origins debate has gone about as 
far as it can go.  Everyone has pretty well elucidated thier opinions, 
evidence, and intellectual approach to the problem.  I don't think there 
is much more to talk about until the appropriate fossils turn up.  

LN Jeff