Re: Podokesauridae, Problems of Nomenclature Returned

["Jaime A. Headden" <qilongia@yahoo.com>]

Mike Keesey (tmk@dinosauricon.com) wrote:

<Ah, but _Coelophysidae_ was *defined* first. (Podokesauridae has never
been explicityly defined, TMK.)>

  It doesn't matter. 1) if Podokesauridae is valid, Coelophysidae is sunk,
in accordance with the ICZN. I believe the Phylocode provision is to move
the definition to the valid taxon to which it applies; 2) The definition
is not a valid reason to retain a taxon in priority, as any rule of
definition application has been established. This may be the desire, but
until I see it applied effectively, I will follow the ICZN.

<Following traditional taxonomy and the ICZN, Familia Podokesauridae is
correct, but following cladistic taxonomy and precedence of definition,
_Coelophysidae_ is correct.>

  Phylogenetic taxonomy says nothing on the application of names and
definitions and the priority of a definition making an un-defined taxon
defunct by it's lack. And if it did, I'd throw a fit. The person who
defined Coelophysidae considered *Podokesaurus* to be an indeterminate
taxon and dismissed it out of hand. Colbert, an expert on *Coelophysis*,
considered them synonymous. So did Paul, and most other workers on these
taxa except for Sereno. When defining taxa where there may be synonymy
issues, the synonymy should be worked out first to avoid such confusion as
above. However, this is no reason to apply a strict glue between taxon and
definition that forces the taxon into use to which a definiton applies.
Bad practice in my opinion.

  I see defining taxa as a supremely advantageous step, but I also would
like to consider it optional to the person who names the taxon. Issues of
synonymy are very important, and they should be clearly worked out before
anyone decides a taxon is not valid in one fifteen-word (or less)
paragraph.

<(There's also the issue, as DinoGeorge notes, of whether _Podokesaurus_
and _Coelophysis_ really are synonyms.)>

  And this may be an issue of examining the material and attempting to
described the casts to see if there's any validity to this, as Mickey
Mortimer spoke to me in private earlier. I can see the perspective, but
personally feel that the material is too fragmentary and poorly preserved
to offer any insight. What apomorphies are present are present in
*Coelophysis* as well, and to a lesser degree *Syntarsus rhodesiensis* as
well. This makes it more than likely to consider *Podokesaurus* a specimen
of *Coelophysis* or "coelophysid." And whether they were synonymous or not
would still need to be taken into consideration. If it's closer to
*Coelophysis* than *Ceratosaurus* as Sereno defines it, then
*Podokesaurus* still wins as the first nominative suprageneric title
holder and Coelophysidae is sunk. The ICZN wins, and Coelophysidae is
lost. Sorry, it's a fun taxon to have, but the rules say otherwise. For
now, anyway.

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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