Taxacom: When to designate lectotypes

[Rosenberg,Gary]

>>Another provision could establish a restriction like in Art. 75.2 for
neotypes, that a lectotype must not be designated as an end in itself,
or as a matter of curatorial routine. This appears to be a quite
successful model in neotypes and has the effect that unnecessary neotype
designations are usually avoided.

A lectotype designation is "taxonomically not necessary" if there is only one taxon (species or subspecies) among the syntypes. By designating a lectotype, one makes in more likely that workers will refer to the same concept. The downside is that if in the future the former syntypes are thought to belong to more than one taxon, it is possible a better choice could have been made for the lectotype. Species are often more finely divided than originally thought, particularly if DNA sequencing is done. But when DNA sequencing has more finely divided a species, there is no guarantee that sequencing would work on the type material (if one can get permission to attempt it). Botany addresses this problem by the use of epitypes.

Assume a lectotype has been designated, one gets permission to sequence it, and the sequencing succeeds. There is no need for a neotype, since the lectotype was sequenced and assigned to one of the species. What if the sequencing doesn't succeed? There are two possibilities: either the original material was consumed in the sequencing attempt or it was not. In the former case, one can designate a neotype, in the latter case one cannot.

I would conclude (agreeing with Frank whose email came in as I was typing), that it is better to have single-name type, so it is better to designate lectotypes.

Best wishes,
Gary




________________________________
From: Taxacom <taxacom-bounces at lists.ku.edu> on behalf of Francisco Welter-Schultes via Taxacom <taxacom at lists.ku.edu>
Sent: Thursday, February 20, 2025 8:53 AM
To: taxacom at lists.ku.edu <taxacom at lists.ku.edu>
Subject: Re: Taxacom: When to designate lectotypes

External.

Dear Paolo,

Code-4 has no clear and unambiguous direct statement to avoid lectotype
designations if they are taxonomically not necessary. Art. 74.3 has a
rregulation that goes in this direction, and declares that designations
must be "specifically for one nominal taxon and must have as its object
the definition of that taxon", others are invalid. This regulation
contains two parts: (1) the designation must refer to the taxon
individually (not by a general statement explaining which specimens in a
chain of various taxa should be the lectotype), and (2) the definition
of that taxon must be the intention.

(Note: The term "definion of that taxon" is inappropriate, the standard
of reference for the application of the name is meant).

If journal editors reject manuscripts with unnecessary lectotype
designations (in situations where the definition of the taxon is clear
anyway) they might have in mind this provision in Art. 74.3.

Another reason to reject manuscripts with a lectotype designation based
on one single syntype may be the literal meaning of the term
"lectotype", in which "lecto" refers to an act of selecting. You can
only select among various specimens, not if only one specimen is present.

With some changes in the next edition of the Code the currently unclear
situation could be improved.
One provision could clarify that a lectotype selection based on one
single syntype would not automatically be invalid for that reason alone.
Another provision could establish a restriction like in Art. 75.2 for
neotypes, that a lectotype must not be designated as an end in itself,
or as a matter of curatorial routine. This appears to be a quite
successful model in neotypes and has the effect that unnecessary neotype
designations are usually avoided.
Finally a new Recommendation could be established that lectotype
designations should be done as part of a revisionary or other taxonomic
work to enhance the stability of nomenclature, and not for curatorial
purposes.

If this helps.

Best wishes
Francisco

Am 20.02.2025 um 08:06 schrieb Paolo G. Albano via Taxacom:
> Dear All,
> as editor of a malacological journal, I often receive manuscripts that
> contain lectotype designations that - in my opinion - are not necessary.
> I think the ICZN Code is somehow vague on the situations where a
> lectotype designation is needed, apart from recommending it should not
> be done for mere "curatorial purposes".
> This ambiguity, and the apparent fondness for lectotype designations of
> some authors, sometimes ends up in a clash with them, and manuscripts
> rejected or withdrawn.
> Is there any paper/chapter/report that discusses in detail the
> situations when lectotype designations are necessary, unnecessary or
> definitely to be avoided? It would help me much in confronting authors
> (or maybe recalibrating my approach).
> Thank you all,
> Paolo
>
_______________________________________________
Taxacom Mailing List

Nurturing nuance while assailing ambiguity for 38 years, 1987-2025.

Send Taxacom mailing list submissions to: taxacom at lists.ku.edu
For list information; to subscribe or unsubscribe, visit: https://nam10.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.ku.edu%2Flistinfo%2Ftaxacom&data=05%7C02%7Ctaxacom%40lists.ku.edu%7C05fec273ec3b4fc33fba08dd51d204f3%7C3c176536afe643f5b96636feabbe3c1a%7C0%7C0%7C638756684645228220%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=gyAMHN1Hf4IWjqfESEz%2FF46vYV2L2Lq8L7Os8AmE40I%3D&reserved=0<https://lists.ku.edu/listinfo/taxacom>
You can reach the person managing the list at: taxacom-owner at lists.ku.edu