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Re: New papers in Geobios (and nomenclatoral gripe)

Christopher Tayler (gerarus@westnet.com.au) wrote:

<This is simply not true. The recognition of a taxon as a _nomen dubium_ is a
subjective, not objective, decision. Nomina dubia retain full taxonomic
availability, though they may not currently be practically usable.>

  The problem is, the issue of a nomen dubium is entirely subjective, including
any treatment whatsoever about how to refer to them, subjectify them, etc. The
ICZN turns a neccessarily blind eye to them. This may be one of those cases.
However, there is enough precedent...

<If the taxon can still be diagnosed at the genus level, then there is no
reason why the genus should be invalid. In the case of the genus _Pantopsalis_
(Arachnida, Opiliones) that formed a large part of my Master's thesis, the type
species _P. listeri_ can't currently be identified at species level due to the
necessary characters not being in the original description (and the type
material is possibly lost). However, the written description supplies enough
detail that I can be sure that it was indeed a _Pantopsalis_, and can still use
the genus as it currently stands with confidence.>

  What good is a genus without a species? Much les a type species? In the
example Chris gave, it seems to be a running convention in massively specific
groups to recognize the validity of the group regardless of whether there is a
valid type species in that genus. At which point the systematist down the road
either takes that route and simply pretends everyone else is correct in knowing
what a species of that genus is, or actually decides to evaluate this by
examining the type species, by which other species must be compared to be
contained in the genus, and finds that *Pantopsalis* will likely implode -- and

  Another example may be derived from *Coelophysis*. The lectotype by
designation (although two different people selected two different lectotypes)
is not specifically viable, and does not bear apomorphies relating to its
comparisons to other specimens included in the genus. At the time, it could not
even be compared decently to other genera. Sullivan and co decided this meant
the species *bauri* was systematically unviable, rendered it a nomen dubium,
and because it was the type species of *Coelophysis*, that genus became a nomen
dubium -- and again, to differentiate a monotypic genus from its species is
ridiculous and calls into question how anyone can distinguish a genus from a
species. This lead the authors to coin a new name for the specimens everyone
THOUGHT was *Coelophysis*, because the specimens contained under *bauri* could
not be included thus since it was itself invalid, and thus was born
*Rioarribasaurus colberti*. It would only come later, years later after *R.
colberti* was used by several papers and accepted, that it was suppressed by
ICZN action due to appeal on the case of consistent use of *bauri*; this could
only be done by designation of a neotype.

  So, if a type specimen is NOT viable for a species, if one is loathe to treat
it as a nomen dubium, one can redesignate the type to a more equitable
specimen. The problem with *M. suessi* is, as Sachs and Hornug state, is that
the Muthmannsdorf specimens are all essentially too incomplete, too juvenile,
or too problematic to serve as viable species, so they are lumped into the
nearest generic container they resemble, which is *Zalmoxes*. Since the type
specimen of *suessi* is not diagnostic to the species level, they refuse to
recognize it as a valid species, and thus it's basically just a part of a
collection of specimens without any other attribution.

  I, personally, would like more clear determinations on how to recognize a
nomen dubium, and what to do with one if this ever occurs, but the ICZN does
not recognize the issue, and leaves this to author's whims. Thus what they do
is not covered under the ICZN, while neotype designation is. Under
typification, the type specimen has to be recognizable and comparable, which in
this case it is not. So, I see no way to make *shqiperorum* (mispelled
"shpiperorum" in Sachs and Hornug) and *robustum* species of *Mochlodon*.


Jaime A. Headden

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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