Taxacom: Nomen novum, homonymy, valid species name and junior synonym

[Douglas Yanega]

On 5/3/22 7:35 PM, André Prado via Taxacom wrote:
> Hello everyone,
>
> I am having some issues on homonomy of spider species, and would be thankfull if you could help.
>
> Regarding the situation below  is it recommended to propose a nomen novum?
>
>   The nomen novum to be proposed is Tibelloides remoiseri, to substitute Tibelloides paraguensis (Gertsch, 1933) (described in Apollophanes), which is preoccupied by Tibelloides paraguensis (Simon, 1897) (described in Tibellus). The problem is that the species from Simon is a junior synonym of Tibelloides punctulatus (Taczanowski, 1872). Although the name from Simon is not a current valid species name, it is available  and, as I understand (based on ICZN Articles 23.3.6 and 23.4), it is subjected to the Principle of Priority.
>         Other taxonomists, however, suggest that  a nomen novum for Tibelloides paraguensis (Gertsch, 1933) is unnecessary, or not recommended, as it would be only proper when, hypothetically, Tibellus paraguensis Simon, 1897 was removed from synonymy, and turned into a valid species in Tibelloides.  I could not find articles in the ICZN dealing with this specific case. And in literature, I just found one similar example by Li & Blick (2019), in which they proposed a nomen novum, Clubiona zhangyongjingi, to substitute Clubiona transversa Zhang & Yin, 1998, which was preoccupied by Clubiona transversa Bryant, 1936, which is a junior synonym of Clubiona maritima L. Koch, 1867.
>
> I am looking for any elucidation on this issue, or suggestions of similar cases judged by the ICZN commission, to have references to base myself on.

The Code often works like a flow chart.

Unless the conditions of Article 23.9.1 apply, a junior secondary 
homonym that is presently preoccupied by a synonym must be replaced, 
following Article 57.3. Article 59 does not apply, as the taxa are 
presently congeneric.

It is therefore necessary to refer to Article 23.9.1, and you do not 
give the necessary details. Specifically, whether paraguensis Simon was 
used as a valid name after 1899, versus whether it was synonymized 
before 1899, and treated as invalid thereafter. (Art. 23.9.1.1)

If the former, then you must either replace paraguensis Gertsch, or 
submit an application the Commission. If the latter, you must then 
assess how often paraguensis Gertsch has been published.

Specifically, if paraguensis Gertsch "has been used for a particular 
taxon, as its presumed valid name, in at least 25 works, published by at 
least 10 authors in the immediately preceding 50 years and encompassing 
a span of not less than 10 years." (Art. 23.9.1.2)

If so (that is, if Art. 23.9.1.1 and Art. 23.9.1.2 are *both* 
satisified), then you can declare paraguensis Gertsch a nomen protectum 
and paraguensis Simon becomes a nomen oblitum and couldn't be used even 
if it is de-synonymized. If not, then you must either replace 
paraguensis Gertsch, or submit an application the Commission.

The Clubiona case is very different, as it is a junior *primary* 
homonym, and those names are assessed and treated under different 
Articles (57.2 and 23.9.5).

Peace,