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Re: Type material: does it have to be pretty?
Phillip Bigelow wrote (11/13/97; 7:41p):
>>Another thing that I want to know about is whether a type specimen
>>can be replaced if a much better specimen is found?
>No. Provided that the crappy material is "diagosable" of something
>never before described, then it stays the type (holotype, actually).
>If the crappy material is later found not to have been diagnostic
>of a unique critter, then it ceases to be a valid taxon (provided
>that someone publishes this fact). The key is diagnosability,
There is another solution to the problem of non-diagnosability in
holotypes. A neotype could be designated. A neotype is (from the
International Code of Zoological nomenclature) another specimen
designated "to be the type (neotype) of a nominal species-group taxon if
no holotype, lectotype, syntype, or prior neotype is believed to exist."
This is what should have been done for Coelophysis bauri (was that the
species?), since the holotype was undiagnosable, rather than erecting a
new genus (Rioarribasaurus) for the species. The latter course, which is
what actually happened until the Commission on Zoological Nomenclature
was asked to intervene, left the better-known name in limbo and possibly
referring to nothing identifiable. Although at first glance it may
appear that designation of a neotype would not be appropriate in this
case (since a holotype existed), it had become clear that the holotype
was inadequate. This is what the Code recommends about such a situation:
"Neotypes should be designated to clarify the application of names when
their continued existence as nomina dubia threatens the stability of
other names; if, despite the existence of a holotype, or a lectotype, or
syntypes, it is not possible to resolve a complex zoological problem, a
zoologist should refer the case to the Commission which may, by the use
of the plenary power, set aside the existing type material and designate
a neotype." (Recommendation 75E)
Recommendation 75B is this: Before designating a neotype, an author
should satisfy himself that his proposed designation does not arouse
serious objection from other specialists in the group in question.
I felt that the authors of Rioarribasaurus should have taken care to be
sure that other systematists were likely to agree with their proposal.
Foreseeing the considerable confusion and disagreement, the matter should
have been brought before the Commission initially, which could then have
designated a neotype for Coelophysis, thereby retaining stability in
nomenclature and continuing to "honor" the originator of the concept (of
C. bauri), who may have been operating according to professional
standards in existence when the name was introduced. (Well, maybe he
wasn't, but we do strive for stability in established names.) The
Coelophysis affair demonstrates (or should have demonstrated) a situation
in which a poor holotype could be replaced with a neotype. Going through
the process requires special effort, but in some cases it is the best
I'm not arguing with Phillip--just supplying more information about this
legalistic loophole to the sanctity of holotypes, and a commentary. I
know that several people on the dinosaur list don't agree with my
position on Coelophysis. So, what's new? At least the subsequent action
of the Commission supports my interpretation of the applicability of
Recommendation 75E to such a situation.
Norman R. King tel: (812) 464-1794
Department of Geosciences fax: (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712 e-mail: firstname.lastname@example.org