Re: Dinofest Report #2 (and final)

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

> Indeed it is, but not for the reason you think.  There are rules for naming 
> species,
> rules enforced by the ICZN.  The first name published has seniority.  Period.
> There are, however, apparently no rules at all for naming clades.  If there 
> were, then
> the naming and usage patterns would make some sense.  They don't.

      The first genus name published has a holotype specimen that is THE
member of that genus, and all other specimens must be of the SAME genus
as the holotype in order to be included in that genus.  Similarly, a clade
has a "holotype" ("all species closer to so and so...".), and all other
taxa included in that clade must form a monophyletic group with the
"holotype" (in the case of Arctometatarsalia, the "holotype" is the
ornithomimids) in order to belong in that clade.  
     Since (if Dr. Sues is right) the elmisaurs do not form such a
monophyletic group with ornithomimids, they are excluded from the
Arctometarsalia.  However, since tyrannosaurs and troodontids apparantly
do, they can stay.  
     Just substitute a genus name for Arctometatarsalia,
specimen numbers for ornithomimids, tyrannosaurs, troodontids, and
elmisaurs, and "same genus as" for "forms a monophyletic clade with" in
the previous paragraph, and you should see the principle is the same.           
     Of course, some of us disagree with the strict cladistic
practice of only recognizing monophyletic groups, and might argue that
paraphyletic groups are also okay, but that is a whole
nother can of worms.  In any case, placing elmisaurs in the
Arctometatarsalia would make it POLYphyletic, and virtually no one likes
that.

LN Jeff
O-