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Re: Say this slowly: theropoda is paraphylitic, theropoda is paraphlyitic.....
At 08:55 AM 6/26/00 -0400, ELurio@aol.com wrote:
The two terms have different meanings. A paraphyletic group is one that
includes the most recent common ancestor of all of its members and of each
pair of members, but excludes one or more monophyletic groups of its
descendents. A polyphyletic group is one that either does not include the
common ancestor of all members, or does not include the common ancestor of
some pair of members.
Let's see, I get told that the term paraphyletic is actually the term
right then you tell me that it isn't. Hmmmmm......
Thus a given the current best cladograms, _Theropoda_ *without* birds is
paraphyletic. A Theropoda consisting of several disjoint clades each
derived from a non-theropod ancestor would be polyphyletic.
May the peace of God be with you. firstname.lastname@example.org