Proposal (811) to South American Classification Committee

Change the specific epithet of Xenops rutilans to rutilus

BACKGROUND: With few exceptions, all major taxonomic lists and publications on Furnariidae and birds of South America in the XX century used Xenops rutilans. Upon rediscovery of bibliographic material of Temminck’s “Les Planches Coloriées d’Oiseaux,” it was found that the name was made available as Xenops rutilus (Dickinson 2011). Temminck published a series of 600 plates illustrating birds, making available hundreds of names, many of which we use today as species names in SACC. The plates were issued in 20 installments (livraisons) followed by an accompanying text. The plates themselves contained a French name for each species so most names (and publication date) have been taken from the accompanying text published later. The recent rediscovery of the wrappers in which the plate livraisons were originally issued and distributed triggered the revision of publication dates and original spellings, as the wrappers showed and index with both French and Latin names for the species included (see Dickinson 2012 for further details). Regarding the present case, the bird depicted in figure 2 of plate 72 was listed as Xenops rutilus in the 1821 wrapper but as Xenops rutilans in the subsequently published accompanying text. Dickinson (2011) concluded that "The name Xenops rutilans Temminck, 1821, … is an incorrect subsequent spelling and must be replaced by Xenops rutilus…” Since then, some lists (Dickinson & Christidis 2014, del Hoyo et al 2016) started to use Xenops rutilus instead of Xenops rutilans.

ANALYSIS:

Dickinson (2011) is right in concluding that rutilans is an incorrect subsequent spelling (see ICZN Art. 33.2 for details). However:

“when an incorrect subsequent spelling is in prevailing usage and is attributed to the publication of the original spelling, the subsequent spelling and attribution are to be preserved and the spelling is deemed to be a correct original spelling.” (ICZN Art. Art. 33.3.1)

Therefore, we need to evaluate whether rutilans has been in prevailing usage. Before Peters, prevailing usage is not clear, as many authorities used rutilans, but some prominent lists like Cory and Hellmayr (1925) used rutilus. However, after Peters (1951) the spelling rutilans became universally used in the scientific literature including taxonomic lists, field guides, books, and papers. It has been only very recently and after Dickinson (2011) publication that the Howard & Moore and BirdLife/HBO lists started to use rutilus. As a numerical evaluation, a search in Google Scholar resulted in only six publications between 1951 and 2019 that used Xenops rutilus as a valid name, in contrast to more than 600 that used Xenops rutilans.

Therefore, Dickinson is incorrect in stating that X. rutilans must be replaced by X. rutilus, as X. rutilans is clearly in prevailing usage and thus protected from priority by Art. 33.3.1.

RECOMENDATION: Because rutilans has been in prevailing usage at least since 1950, it is protected by ICZN Art. 33.3.1 and should be considered the “correct original spelling.” There is no justification for reverting to rutilus. Therefore, I recommend a NO on this proposal.

REFERENCES:

Dickinson, E. C. 2011. The first twenty livraisons of “Les Planches Coloriées d’Oiseaux” of Temminck & Laugier (1820-1839): II. Issues of authorship, nomenclature and taxonomy. Zoological Bibliography 1(4):151-116.

Dickinson, E. C. 2012. The first twenty livraisons of “Les Planches Coloriées d’Oiseaux” of Temminck & Laugier (1820–1839): IV. Discovery of the remaining wrappers. Zoological Bibliography 2(1):35-49.

Santiago Claramunt, January 2019

Comments from Robbins: “NO: rutilans has been in usage for so long that reverting to rutilus will only add confusion. Nothing in committee correspondence (via email) has swayed me from simply going with prevailing, long-term usage.”

Comments from Areta: “YES. This is a minor change that does not alter the communication value of the name, is easy to accommodate and assure us that we are complying with the principle of priority, which is in several respects more robust than the indiscriminate use of the ill-defined ad-hoc prevailing usage possibility.”

Comments from Stotz: “NO. I favor maintaining the long-term prevailing usage.”

Comments from David Donsker: “Santiago’s conclusion is that “rutilans” has been in prevailing usage at least since 1950, and is thus protected by ICZN Art. 33.3.1. But I believe that this is an incorrect interpretation of the code as in regards to its definition of “prevailing usage”.

Santiago’s proposal does not reference Article 23.9.1 of the Code which requires that two conditions be met in order to maintain prevailing usage. Specifically, these are: that the senior synonym or homonym has not been used as a valid name after 1899 AND, that the junior name has been used in at least 25 works published by at least 10 authors in the immediately preceding 50 years in a span of not less than ten years.

The specific wording of Article 23.9.1 is here:

23.9.1. prevailing usage must be maintained when the following conditions are both met:

23.9.1.1. the senior synonym or homonym has not been used as a valid name after 1899, and

23.9.1.2. the junior synonym or homonym 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.

While the second condition of Art. 23.9.1 is undoubtedly met in this case, the first condition is decidedly not. The specific epithet Xenops rutilus has certainly been used subsequent to 1899 as pointed out by Santiago himself: “…many authorities used rutilans, but some prominent lists like Cory and Hellmayr (1925) used rutilus”.

“Thus, both conditions of Art. 23.9.1 are not met, so prevailing usage as defined by the Code cannot be invoked in this case. The observation that “rutilans has been in prevailing usage at least since 1950” is simply not germane to the Code as the ICZN defines “prevailing usage”.

“I believe that Dickinson’s (2011) conclusion that "The name Xenops rutilans Temminck, 1821, … is an incorrect subsequent spelling and must be replaced by Xenops rutilus is the correct interpretation of the Code, and that YES would be the appropriate vote on this proposal.”

Comments from Piacentini: “NO. A minor correction to David Donsker's comment: article 23.9 (and its subarticles) deals with reversal of precedence (by two different names), NOT prevailing usage (in this case, by two different spellings). That means that the temporal window cited in the articles in question apply when dealing only with such a reversal. On the other hand, the definition of "prevailing usage" is given in the Glossary, as follows:

‘usage, prevailing, n. Of a name: that usage of the name which is adopted by at least a substantial majority of the most recent authors concerned with the relevant taxon, irrespective of how long ago their work was published.’ [bold mine]

“As such, Claramunt's recommendation is fully endorsed by the Code, and I strongly support it. There was no need for Dickinson (in this or similar cases) to revert the spelling to the long-abandoned original spelling once the ISS was in prevailing usage. Rather than solidifying the universality of the prevailing usage of rutilans, Dickinson's act has only brought instability to a case that had already been historically set.

“Were it a case of two names by two distinct authors competing to be the valid one, or a case to correct the original date of publication (such as the Pteroglossus beauharnaesii case), then I could have a different opinion. But to abandon a name widely in use because an alternative spelling has been discovered to be original (after perhaps over a century without anyone aware of any original wrappers left) is unfortunate, in my view.”

Comments from Claramunt: “Regarding David’s comment: Article 23.9.1 is not relevant here because we are not dealing with synonyms (two different names applied to the same taxon) nor with homonyms (the same name applied to two different taxa). Here we are dealing with different spelling of the same name. In other words, X. rutilans Temm. 1821 and X. rutilus Temm. 1821 are not synonyms but alternative spellings. When stating the Principle of Priority, The Code distinguishes between “Application to Synonymy” (Art. 23.3) and “Application to spellings” (Art. 23.5), so these two different cases should not be confused. Note that Dickinson also correctly pointed out that “Art. 23.9, which might be thought relevant, relates to different names not to different spellings of the same name and here we are concerned only with Temminck’s two spellings of the same name.” (Dickinson 2011: 157). Therefore, those more stringent conditions stipulated in Art. 23.9 do not apply here. However, Dickinson (2011) was incorrect in stating that rutilans “must be replaced” by rutilus, as the former is in prevailing usage and therefore protected from priority by Art. 33.3.1.”

Comments from Areta: “This exchange of opinions substantiates my arguments on the lack of solid criteria when dealing with the application of prevailing usage. If we have to look into the glossary to learn what to do, then we are in trouble. As I stated in one of the e-mails, reversal of precedence has clear application guidelines, whereas prevailing usage is more or less in the realm of an arbitrary ill-defined limbo: no clear guidelines, no temporal frame, no publication counts, etc. Also, it seems a strange feature of The Code: to allow the perpetuation of an “original sin” just because it has become widespread. This is quite a unique situation in that it changes the validity of an act by applying a double and contradictory criterion: if little time has passed the incorrect subsequent spelling is punished, but ex post facto is deemed correct by recurring to a mechanism (widespread usage) to bring it back to life, when it would have been declared dead at birth. I am of the opinion that prevailing usage should not be used for all the cases involving minor changes in spellings, especially because I doubt that stability and communication are compromised in any meaningful way.”

Response to Areta from Claramunt:

“If we have to look into the glossary to learn what to do, then we are in trouble.”

“There is nothing wrong with looking into the ICZN Glossary. The Glossary is integral part of The Code where key definitions are provided. Check the ICZN Introduction.

“As I stated in one of the e-mails, reversal of precedence has clear application guidelines, while prevailing usage is more or less in the realm of an arbitrary ill-defined limbo: no clear guidelines, no temporal frame, no publication counts, etc.”

“When the ICZN is more relaxed, it gives taxonomists (us) more freedom. It could be a good thing.

“Also, it seems a strange feature of The Code: to allow the perpetuation of an ‘original sin’ just because it has become widespread.”

“Actually, unconditional adherence to the original spelling could perpetuate typographical errors, orthographical errors and other types of “sins.” Many subsequent spellings are corrections to such original errors. Not a bad thing, in my opinion. Systematic ornithologists of the 19th and early 20th century, many proficient in Latin, did a tremendous job at building avian taxonomy from the chaos of earlier publications. If they decided that rutilus should be spelled rutilans, I take their word.”

“This is quite a unique situation in that it changes the validity of an act by applying a double and contradictory criterion: if little time has passed the incorrect subsequent spelling is punished, but ex post facto is deemed correct by recurring to a mechanism (widespread usage) to bring it back to life, when it would have been declared dead at birth.”

“It is perfectly sound, in my opinion. The Code favors the status quo, thus preserving stability. Priority is only a tool to attain stability. Priority is not useful if it disrupts stability for no good reason. Prevailing usage would also align with the accepted consensus among taxonomist. Again, I think we should view prevailing usage as a way of putting more emphasis on the users (consensus among taxonomists) rather than imposing an abstract hard rule from the Code.”

“I am of the opinion that prevailing usage should not be used for all the cases involving minor changes in spellings, especially because I doubt that stability and communication are compromised in any meaningful way.”

“Respectable opinion but as long as Art. 33.3.1 is in the Code, prevailing usage cannot be just ignored.”

Response from Areta:

“Yes, we are in trouble if the main guide is the glossary definition. Yes, perfectly fine to look for words there. But, terrible if the main guide is just the definition.

“There are various empty words here: ‘stability’, ‘prevailing usage’, etc. Stability from now on? Stability looking backwards? Prevailing usage by whom? In which time-frame? etc.

“I love the freedom that The Code allows. But it should be used with care. My sensation is that advocating prevailing usage as a main guide for nomenclatural decisions is problematic.

“The Code favors the status quo, thus preserving stability"

“May or may not be. Stability is complex, not a horizontal concept, but rather one that should be understood across time.

"I think we should view prevailing usage as a way of putting more emphasis on the users (consensus among taxonomists) rather than imposing an abstract hard rule from the Code"

“The problem is that PU is not restricted to consensus among taxonomists, but rather to the massive use by non-taxonomists (or this seems, since there is no clear definition other than being prevailing because it prevails...). My problem with PU is that relies on commonsense, which varies from place to place, time to time, and person to person.”

"Actually, unconditional adherence to the original spelling could perpetuate typographical errors, orthographical errors and other types of “sins.” Many subsequent spellings are corrections to such original errors."

“That is why The Code distinguishes types of emendations. They are not all the same, no problem with that. Ah, oh, but then PU plays the double-moral game. And if the correction produced another error but is widely used? It is not so simple. Also, The Code specifically forbids correcting many of these errors.

“My main point here is that prevailing usage should be used critically, and I envision it being useful in difficult cases where the communication value of a name is compromised. But yes, it is a matter of opinion, and because it is so, I would not argue that it will, in general, bring about stability or agreement. Was it not for the merging of IBC and eBird and the possible taxonomic changes that this might mean, prevailing usage would have taken us quickly on a very different road. Dangerous and labile.”

Comments from Zimmer: “ “NO. Prevailing usage should trump priority in this case, in my opinion.”

Comments solicited by Areta from Edward C. Dickinson:

“While I believe WGAN interprets the Code in the way that Piacentini puts forward; the IUCN Commissioners have been and I think still are divided on this subject (and indeed on many others). So here are some comments which you may put forward with my name attached.

“(1) It is argued quite correctly that Art. 23.9.1 is not applicable to this case. However, note that this is the only clause that contains a methodology that can be reasonably easily applied to discuss cases that fall under it. Note however that this methodology is not replicated in relation to anything as different as the subject of Xenops. It also follows that 23.10 and 23.11 do not apply to other cases than those covered in Art. 23.9.

“(2) With the irrelevance of 23.9.1 established note that the “not used after 1899” clause in 23.9 cannot be applied – from this article to the Xenops case or indeed to any case without the remit of Art. 23.9.

“(3) I would also observe that care needs to be exercised when dealing with or considering ‘dualities’; in my opinion the Code is often wrongly interpreted to apply to spelling differences rather than name differences. Worth study! This case, we would all I think agree, is one of spelling differences.

“(4) Art. 32.4 helps one to determine if an original spelling is to be considered as incorrect. It is incorrect if something in Art. 32.5 fits the case; to maintain the original spelling all that is needed is to be sure the clauses making up this article do not give cause to show the original spelling to be incorrect and to need change. As far as I can recall I found no cause; checking now I see nothing. Accepting a name from before 1899 and little used after that is perfectly accessible.

“(5) This then brings us to Prevailing Usage. The Glossary definition is all that is germane to this (once we have agreed that this case is not covered by Art. 23.9. It says “usage, prevailing, n. Of a name: that usage of the name which is adopted by at least a substantial majority of the most recent authors concerned with the relevant taxon, irrespective of how long ago their work was published”. Note (a) that there is an apparent (deliberate or accidental) conflict between ‘most recent authors’ and ‘irrespective of … ‘; this could be better determine IF there was a definition of “concerned with the relative taxon” and its application to a case. Over past years many have asked whether the author of a field guide or a national or global checklist is concerned with the relevant taxon. Use of the word suggestion might seem to imply that the works to consider are those that deal with taxonomy. However regardless of whether casual mention in an article dealing with bird song or bird behaviour could qualify the problem many others may have is whether – given the ‘apparent permission to take in works that are “concerned with the relative taxon” and to do so “irrespective of how long ago their work was published” it is obvious that all sorts of opinions gave be honestly put forward for how to resolve this sort of situation.

“(6) When the Howard & Moore team and the BirdLife Lynx team collaborated on the examination of two hundred or more cases of names that were in use in two spellings those of us engaged (Andy Elliott, Normand David and myself) decided that it would be presumptuous to try to judge these cases when a 5^th edition of the Code is being developed. These views were shared with some ICZN Commissioners known to be on the editorial committee for the Code (I copy four of them herein as a reminder). I remain hopeful that the coming Code edition will benefit – or has already benefitted – from serious discussion of this impasse by the ICZN’s editorial committee.

“Best wishes, Edward”

Additional comments from Claramunt: “A final reflection regarding the use of priority versus prevailing usage in this case. The detailed analysis by Edward (Dickinson 2011, 2012) exposes the complexities of determining authorship and date of publication for the names introduced by Temminck. The name X. rutilus appeared first in Lichtenstein (1819) but as a nomen nudum because no description or association with a real taxon was made. The name was definitely made available by Temminck in the text of his collection of plates, published in 1823, as X. rutilans. These are the date and authorship that are usually recognized. There is no ill judgment or bad intentions by later authors in accepting this name.

However, the plates themselves were published and distributed before the text, as revealed by records of museums of having received the plate installments before 1823. Plate 72 figure 2 illustrates X. rutilans but without a Latin name, so the plate by itself did not made the name available. However, the wrappers of the plate installments did list the species using a Latin name, but it was not until recently that the wrappers were rediscovered, because typically the wrappers were discarded, and the different installments were bound in a single final volume. In the wrappers of installment 12, plate 72 fig. 2 is indicated as an illustration of X. rutilus (using a Latin name). Installment 12 is estimated to have been published in 1821 (see Dickinson 2011 for details about how this estimate was made). Therefore, Dickinson (2011) proposed X. rutilus Temminck 1821 (instead of X. rutilans Temminck 1823) as the correct way of referring to this taxon, and that triggered the suggestion of using rutilus instead of rutilans, based on priority.

“However, even ignoring prevailing usage, this conclusion is far from being uncontroversial. Critically, it is doubtful whether the wrappers qualify as a valid publications under ICZN rules. In particular, publications “…must be issued for the purpose of providing a public and permanent scientific record (Art. 8.1.1). And it can easily be argued that those wrappers were not issued as permanent components of the final work but for protecting the plate temporally and to be later discarded once the different installments were bound together in the final volume. My point is that if one prefers to follow clear rules and avoid making judgments, it may be better to use X. rutilans Temminck 1823 anyway, as this would be the least controversial introduction of the name, as oppose to dealing with plate wrappers with imprecise publication dates and unclear status as valid publications (Art. 8.1.1).”

Comments from Stiles: “NO. I agree that stability should take precedence, especially given that the original, virtually forgotten first presentation of rutilus was likely an error.”

Comments from Pacheco: “A reluctant NO. I would greatly appreciate if the Code one day contains clear rules for deciding on valid use in cases like this. Personally, I appreciate that there is a zeal to maintain prevailing usage when there are spelling questions involved, although the greatest source of the real "instability" of the names (Scientific / English) are the phylogenies.”