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RE: Gastroliths (Theropods) -Reply

>>> "Thomas R. Holtz, Jr." <th81@umail.umd.edu> 04/20/99 07:27am >>>

Gastroliths are minimally a basal archosaur character (crocs got'em, birds
got'em, so the simplest evolutionary answer is that the most recent common
ancestor of cros & birds had'em).

Correct me if I'm wrong, but I think this kind of reasoning from parsimony only 
works when you're dealing with homologous structures (physical or molecular).  
It loses a great deal of force when you apply it to behaviors, or to 
non-homologous structures since there is no necessary implication of a common 
genetic basis for the trait.  I study paleontology.  You study paleontology.  I 
can almost promise you that our LCA did not.

  --Toby White