About the genus Cordulegaster

About the genus Cordulegaster

Documents

  • Dumont H.J. 1976Aeschna charpentieri Kolenati, 1846, a synonym of Cordulegaster insignis Schneider, 1845, and on the correct status of Cordulegaster charpentieri auctorum (Anisoptera : Cordulegastridae). – Odonatologica, 5 (4) : 313-321. – [PDF]
  • Fraser F.C. 1929 – A revision of the Fissilabioidea (Cordulegastridae, Petaliidae and Petaluridae) (Order Odonata). Part I. – Cordulegastridae. – Memoirs of the Indian Museum, IX : 69-166. – [PDF]
  • Lohmann H. 1993 – Revision der Cordulegastridae. 2. Beschreibung neuer arten in den Gattungen Cordulegaster, Anotogaster, Neallogaster und Sonjagaster (Anisoptera). – Odonatologica, 22 (3) : 273-294. – [PDF]
  • Morton K.J. 1916 – Some Palaearctic species of Cordulegaster. – Trans. Ent. Soc. Lond., III-IV [1915] : 273-279. – [PDF]
  • van Pelt G.J. 1994 – Further notes on Chinese Cordulegastridae (Insecta: Odonata: Anisoptera). – Zool. Med. Leiden, 68 : 87-96. – [PDF]

Initial message of V.Kalkman missing.

The type locality, of course, is also a major port with deep historic ties to Europe, most famously with the German brewery that has been providing China’s most famous beer since 1903: Tsingtao! If the holotype is identical to one of the forms of boltonii, I’d say you can dispose of it!

I’m okay with the other suggestions, although it’s always hard to find a place to park doubtful taxa like magnifica. If only the same authors hadn’t just created all those doubtful taxa of their own, then it would simply have become a synonym of insignis… :o/

K.D.Dijkstra (January 5, 2022 – 10h42)

Based on the recent revision of Cordulegaster in the eastern part of the Western Palearctic I was triggered to check the World Checklist. Based on that I have several proposals for changes. The first three are merely based on following the taxonomy being used by Haomiao Zhang in his 2019 book. He knows these taxa best and judges them to belong to Neallogaster (I agree with that). The fourth proposal is based on a hidden remark in the recent Cordulegaster paper.

  • Cordulegaster annandalei (Fraser, 1923) > Neallogaster annandalei (Fraser, 1923). This species is included in Zhang 2019 as Neallogaster annandalei (including images that clearly belong to Neallogaster). I did not check this in detail but trust the judgement of Haomiao.
  • Cordulegaster lunifera Selys, 1878 > Neallogaster lunifera (Selys, 1878)
  • Cordulegaster jinensis Zhu & Han, 1992 > Neallogaster jinensis (Zhu & Han, 1992)
  • Cordulegaster magnifica Bartenev, 1930 (doubtful species) > delete. Schneider et al 2021 write: ‘For C. magnifica, described by Bartenev based on a single female of unknown origin, we did not find any support in the investigated region [28]. The type is lost. The description fits to most females of ‘mid-yellow’ Cordulegaster of the bidentata-group in the East Mediterranean, the Middle East and the South Caucasus. In view of its unknown origin and as no other specimen or living population’.

When these changes are made we get a relatively straightforward situation with the Cordulegastridae in which we have three genera:

  • Cordulegaster, containing four groups (Neartic, bidentata, boltonii and coronata). The easternmost representative of Cordulegaster is brevistigma and parvistigma (the only two not yet placed in one of the four mentioned groups) which occur as far east as NW India.
  • Anotogaster which is found in the eastern Palaearctic occurring as far west as Nepal and easy to recognise based on the lack of an anal triangle in the males (present in all other genera) and the rather simple pattern on the abdomen (a single ring on each segment). 
  • Neallogaster which is centered on the Himalayan region and the mountains of China mostly occurring at higher altitudes. These species are relatively small, hairy and have a pattern of pairs of spots high on the dorsum of the segments which is clearly different from the pattern of Anotogaster. Most (all?) of these species have hugely inflated frons which is wrinkled on front. It seems that this inflated frons is an adaptation to higher altitudes and is more expressed in species occurring higher up (a similar situation is found in Cephalaeschna). 

The only exception to this nice and clear situation is Neallogaster orientalis. This species is only known from a single specimen from Shandong province in the east of China, thousands of km away from the nearest true Cordulegaster. However, according to van Pelt (1994) it is close to the European boltonii. Zhang (2019) placed it in Neallogaster but I do not think this was based on new information and I propose to keep it in Cordulegaster maybe stating that it is a problematic species. There are two possible explanations: (1) it is a true species and a relict of a once wider distribution of the Western Palaearctic group or (2) it is a mislabelled specimen. With the increased amount of fieldwork in China and the fact that nothing resembling it has been found I tend to go for option 2. The problem is of course that absence of proof is no proof and as long as no new specimens are found there won’t be a solution. A possibility might be to do DNA work to see if it indeed falls into boltonii – but of course that is not easily done with a holotype. 

V.Kalkman (January 5, 2022 – 17h19)

Attached is the image of the holotype of Cordulegaster orientalis and the original description. If you compare this with the drawings in KD’s field guide you will see that it is near identical to C. boltonii. A weird situation.

© Vincent Kalkman
© Vincent Kalkman

van Pelt G.J. 1994 – Further notes on Chinese Cordulegastridae (Insecta: Odonata: Anisoptera). – Zool. Med. Leiden, 68 : 87-96. – [PDF]

V.Kalkman (January 5, 2022 – 17h27)

Thanks for bringing this to our attention! Since there is a source (Zhang 2019) supporting these first 3 changes, like KD, I see no problem with it. I can make notes justifying the placement. For Neallogaster orientalis I think it would be best to leave it in Neallogaster (following Zhang), but I can again add notes (including a visible one) about it.

PS : Also note that Cyrille had joined the team and I’ve cc’d him. I’ll forward the images you sent to him as well.

J.Abbott (January 5, 2022 – 17h53)

Note that the full Schneider et al. (2021) quote is “For C. magnifica, described by Bartenev based on a single female of unknown origin, we did not find any support in the investigated region [28]. The type is lost. The description fits to most females of ‘mid-yellow’ Cordulegaster of the bidentata-group in the East Mediterranean, the Middle East and the South Caucasus. In view of its unknown origin and as no other specimen or living population is known, it is not possible to ascribe it to any taxon and the name should be deleted.”

That’s sloppy as “deletion” isn’t a taxonomic action, but as we have informally suppressed a few other taxa like this, I guess we can give a similar treatment based on this? And if not, at least the reference can be used to leave it out of Neallogaster.

K.D.Dijkstra (January 5, 2022 – 18h02)

I was actually just struggling with this in TaxonWorks. C. magnifica should really be synonymized (not deleted). I wonder if the better approach is to leave it in the list, but as doubtful, until someone does formally synonymize it.

J.Abbott (January 5, 2022 – 18h08)

Well, it’s one of those taxa that are both not diagnosable and “unsynonymisable”: there’s no specimen, no locality, and the description could fit a number of species, but it’s not a nomen nudum either. So sweeping it under the rug is the easiest. Unless someone formally makes it a synonym of insignis, of course, but even for that there’d technically be no evidence, so it might never happen…

K.D.Dijkstra (January 5, 2022 – 18h19)

It’s problematic for sure, but a formal name that is out there, so I don’t like the option of just deleting it. I think we need to document it, if for no other reason so that we or someone else doesn’t revisit it in the future. I can make it “invalid,” which is technically true, but would accomplish our immediate goals of removing it from the WOL while leaving it in TaxonWorks.

J.Abbott (January 5, 2022 – 18h23)

I agree with KD that it would be best to synomise C. orientalis. I therefore propose to keep C. orientalis in Cordulegaster for the moment. I will then check the holotype and make a note for notulae officially synonymising it. In the same note I will try to bury magnificus. The latter can’t be done in a clean way and I will simply make it a synonym of the most likely candidate (no one will be able to prove me wrong).

V.Kalkman (January 5, 2022 – 18h50)

The case of the genus Cordulegaster is certainly one of the most complex among the Odonata, as far as taxonomy is concerned. My opinions are for the moment only a few hypotheses and still deserve reflection and various control readings. I did not think to tackle the details of this difficult genus immediately, but since the question arises I will do so. I am not sure that in some cases we have not gone a little too fast.

For example the exhumation of Cordulegaster charpentieri does not seem to be the best idea at the moment. It is a nomen ambiguum (see Dumont 1976) which has been a millstone around our neck for over a century and a half, that has been redefined by Schneider & al. (2021) (stat. nov.). A new name (nomen novum) seems to me in this case a more elegant and correct solution.

For example again the article by Froufe & al. (2013) probably sweeps away some subspecies related to Cordulegaster boltonii a bit quickly. I think in this case Cordulegaster algirica deserves to be maintained and might even come close to being a good species. This article is too brief and does not clearly present all the results that were available to the researchers.

The American species could belong to a genus not yet defined (Thecaphora ?). There may even be two genera!

Several Far Eastern Asian species classified in the genus Cordulegaster could belong to Neallogaster and I do not know anything to say whether or not (or in any case I have not read everything on the subject): Cordulegaster jijensis, Cordulegaster orientalis in particular. I have a really reserved opinion on the question that I confess not to have dug yet.

The case of Cordulegaster magnifica must be treated logically on the minimum known, that is to say its textual description and treated in the manner of satellite taxa which haunted Aeshna juncea (cf. Aeshna baicalensis, Aeshna undulata which were resolved by Belevich 2005). This should be coupled with a careful examination of the individuals present in the region supposedly occupied by this phantom taxon.

The study of Cordulegaster from the Italian peninsula, and neighboring islands as well as the Balkans is still very insufficient. There are punctual articles that deserve a better synthesis. I have had some problems with individuals in the French Alps who did not fit in. No study has been done on this last subject.

I have not yet read Morton (1916) and I think it is necessary to do so. Lohman’s paper (or papers I can’t remember) from the 1990s were quickly dismissed by the authors and certainly deserve a better review.

There are some clear things that emerge from the Schneider & al. (2021) paper, others less so and some taxa seem (from memory) to be omitted like Cordulegaster picta. I have to read it again carefully.

It’s a fascinating topic that I’ve already seen several revisions on. I’ve already struggled several times to clarify. The current consensus on the WOL (old version) seems to me to be the most correct at least quickly reviewed: it is consistent with what has been recently published in my opinion. I will therefore make the effort of the necessary readings and search for the articles I am missing. Furthermore, I think that we should create a forum (I can do that !) where the discussions would be archived step by step and would allow to put in form decision procedures.

C.Deliry (January 6, 2022 – 8h25)

Thanks for your informative comments and thoughts about Cordulegaster! I think the idea of a forum where these discussions can be archived is a good idea. I’m documenting things in TaxonWorks, but certainly not at the level of the discussions. One thing I do want to be clear on, we have all decided that we want to let the literature guide us within this group. That is to say, we (as a group) are not wanting to make unilateral decisions, but would prefer things get published and then we base the list on those peer-reviewed publications.

Thanks for offering to setup a form where our discussions can be archived!

J.Abbott (January 6, 2022 – 15h17)

Cyrille has gone through and critically looked at Cordulegaster. See his notes below. There are a number of items here and I would like to get the group’s consensus. I have added Vincent for his input as well, as he initiated the discussions with this group. I don’t see anything that I take issue with and think Cyrille has backed up all suggested changes well…but again, I want to make sure there is wide agreement. Some of the suggestions below overlap with or involve the taxa Vincent wrote about. I am in favor of KD and Vincent’s plan for C.orientalis & magnifica.

“best to synomise C. orientalis. I therefore propose to keep C. orientalis in Cordulegaster for the moment. I will then check the holotype and make a note for notulae officially synonymising it. In the same note I will try to bury magnificus. The latter can’t be done in a clean way and I will simply make it a synonym of the most likely candidate (no one will be able to prove me wrong).”

Cyrille has also created a forum by which we can document changes and discussions in an easily digestible format. See, https://www.odonates.net/wolf/ I like this and would suggest we should even make it public (in a read only format). What are your thoughts?

On 01/07/2022 8:17 AM Deliry wrote: [extracts only]

I have worked a lot in the last 48 hours on the Cordulegaster and I think I have controlled almost everything that can be controlled. We arrive at a concensus very close to what was already on the (OLD) WOL with… one synonym protonym to correct: Cordulegaster bidentatus sicilicus Fraser, 1929, the placement as doubtful (solution 1) or better (solution 2) the displacement of a synonym which is Cordulegaster annulatus race intermedius Selys, 1857, the completion of a synonym protonym which is Cordulegaster insignis nobilis Morton, 1916, the deletion of a doubtful species and its displacement as a synonym with Cordulegaster magnifica Bartenev, 1930 (I had wanted to resolve this case for a long time! ) and finally the good validation of a species considered doubtful, although here my opinion (to be adjusted) is that there is an error somewhere with Cordulegaster orientalis van Pelt, 1994.This is certainly the most complex example I have examined in odonatology, but we will have other taxonomic «  monsters »  to see in the future such as the Tramea for example.

All is represented below with adapted comments. All I say is yet published !

Actually the complex Cordulegaster picta / insignis / charpentieri is still misinterpreted and for me the recent exhumation of Cordulegaster charpentieri is not a good idea at all. I would have made a replacement nomen novum because all the literature is unreadable otherwise.

I re-read the recent monumental paper by Schneider & al. (2021). I think everything is consistent with the presentation of taxa and their synonyms adopted below. I do not see any fundamental error, or even detail, including in the technical redefinition of Cordulegaster charpentieri, recast de novo (for me it is the too ambiguous name that is problematic = nomen ambiguum).

Revision of the list [usefull extracts only]

  • Cordulegaster bidentata Selys, 1843
    • Syn Cordulegaster bidentatus sicilicus Fraser, 1929 – By the source (Fraser 1929).
  • Cordulegaster boltonii (Donovan, 1807)
    • Syn Cordulegaster annulatus intermedius Selys, 1857 – This synonymy is probably not correct. First of all, it is necessary to mark it as such : first possibility. Currently the westernmost “eastern” taxon of the charpentieri / insignis complex is Cordulegaster picta, so it is with this one that the synonymization must be done. Cordulegaster annulatus intermedius (a balkanic form) is therefore synonymous with Cordulegaster picta = second possibility which is the must correct. (see Fraser 1929 too but we need to make some interpretation with for exemple Askew 1988 – Dragonflies of Europe. – Harley, Colchester.)
  • Cordulegaster chapentieri (Kolenati, 1846)
    • Cordulegaster insignis nobilis Morton, 1916 – By the source (Morton 1916).
  • Cordulegaster insignis Schneider, 1845
    • Syn Cordulegaster magnifica Bartenev, 1930 – Synonymised by Lohmann (1993).
  • Cordulegaster magnifica Bartenev, 1930 (doubful species) – This taxon is a «  fantom », without locality and museum type. It is proposed as synonym of Cordulegaster insignis by Lohmann (1993). The difficulty is that author by author, it is a question of understanding how he has interpreted each taxon: what is Cordulegaster insignis for Lohmann (1993) ? Insofar as this author, treats without (co)synonymy Cordulegaster charpentieri and Cordulegaster insignis, his concepts are close to the current vision. Consequently his interpretation is transferable to the present context : this is a synonym of Cordulegaster insignis.
  • Cordulegaster orientalis van Pelt, 1994 (doubtful species) – This species is very probably in the genus Cordulegaster despite the fact that it is a « far » oriental species. There is no doubt on it, the only problem is that seems like Cordulegaster boltonii and is describe by a single specimen, not find again in spite of research, in a very modified region so that one can even imagine that it has disappeared. There is probably no problem of labeling. See van Pelt (1994). For me it is one problem somewhere ! It seems however well to be a Cordulegaster boltonii mislaid in the collections. But… these arguments are not published ! 
  • Cordulegaster picta Selys, 1854

C.Deliry to J.Abbott and D.Paulson (January 7, 2022 – 17h18)

J.Abbott (January 10, 2022 – 21h51) + sending to the team

See joined and the plates : what differences with the structure of appendages of Cordulegaster boltoni are with Cordulegaster orientalis ? Sorry if it is a bad question ! Except for the bad condition of the individual I can’t see any difference.

van Pelt G.J. 1994 – Further notes on Chinese Cordulegastridae (Insecta: Odonata: Anisoptera). – Zool. Med. Leiden, 68 : 87-96. – [PDF]

C.Deliry (January 10, 2022 – 22h03)

I think using Notulae for the publication of the reasoning behind the WOL decision in this complicated group of species is excellent practice. We should do that every time.

C.Bota Sierra (January 10, 2022 – 22h18)

Last week I already prepared a short note for Notulae on orientalis and magnifica which is nearly ready to be submitted (so published mid June?). Tomorrow I will check the type of C. orientalis. The description is really weird in the sense that it states several times that the characters are similar to C. boltonii. In the end it even states: It resembles the European C. boltonii in many characters. In fact, it possesses all apomorphic characters of imagines separating the monophyletic C. boltonii species-group from other cordulegastrids (shape of the superior appendages; anal triangle normally with five celles; the (possible) presence of a humeral spot). It therefore belongs to this species-group. It cannot be associated with one of the known representatives of this group, so the possibility of a locality error is excluded.

The last sentence is odd as the pattern matches that of specimens found in NW Europe and nowhere in the description anything is mentioned on a character not matching boltonii. Tomorrow I will check the type. If this matches C.boltonii I will contact Gert Jan van Pelt to see if he agrees and would be willing to co-author the note.

V.Kalkman (January 10, 2022 – 22h41)

I didn’t respond to Cyrille’s Cordulegaster email because I didn’t see any suggested changes that weren’t already covered by what Vincent wrote.

K.D.Dijkstra (January 12, 2022 – 16h07)

I didn’t see Vincent’s email below about the C. orientalis note he has prepared for Notulae and checking on the type. I think it is really best practice to hold off on dealing with that taxon until the note is actually published. Any objections?

J.Abbott (January 12, 2022 – 16h18)

  • No objection on my part.

D.Paulson (January 12, 2022 – 19h50)

  • I also agree. The general rule should be: no changes unless officially published.

V.Kalkman (January 12, 2022 – 19h53)

Yes, a publication seems to be necessary before changing the information on a taxonym. However, it is also important to draw attention to the taxonym either by stating that it is questionable (doubtfull) or that a revision is in progress, revisions in press or any other information that shows that it should not be used uncritically. I see that you agree on a probable resemblance between Cordulegaster orientalis and Cordulegaster boltonii: a stray in the collections probably then!

C.Deliry (January 12, 2022 – 17h48)

Cyrille did not see my initial mail on this subject and it seems that we reach the same conclusion independently. Cyrille raised the question on whether or not to state if groups or species are under revision or need revisions. In my opinion this would not work, at least not as part of the main/core list. There are simply too many taxa which still need some revision and many revisions in progres never see the light of day.

V.Kalkman (January 12, 2022 – 19h50)

I agree Vincent, while I can see the benefit (both to us and to the general community), it is really beyond the scope of what is feasible of run to keep track of who is revising what. I can always make notes in TaxonWorks that are only visible to us. This would be done easily on a case by case basis.

J.Abbott (January 12, 2022 – 20h02)

The convergence of opinions is a very good sign: that we are approaching the « right » solution. It is necessary to examine the copy in collection or less well, to make an opinion starting from the plate published in 1994 for Cordulegaster orientalis. In fact, all taxa are subject to revision: it is the very principle of a science in progress. I simply wanted to say that it was necessary to mark the few examples on which there are arguments in favor of a doubt : it is currently the case of Cordulegaster orientalis. These taxonyms are identified by the doubtful mention on the first version of the WOL and there are a limited number of them like Heteragrion ovatum, Coenagrion melanoproctum, Epiophlebia diana, etc. That is all.

C.Deliry (January 12, 2022 – 20h30)

To add to that, I would say that anyone who knows of any others like those we are calling “doubtful species” should bring that to the group’s attention, and we can so label them. If we want to add a note in TaxonWorks about why someone considers it doubtful, I think that would be appropriate.

D.Paulson (January 12, 2022 – 20h37)

Unless I misread it, van Pelt says that orientalis is a true Cordulegaster and not a more oriental genus : Neallogaster seems a bad solution. As for Cordulegaster charpentieri, indeed it is best to rely on the decisions of the new status given to this taxonym by Schneider & al. (but it is something like Cordulegaster charpentieri sensu Scheider & al. 2021 nec auct. and probably in accordance with the original version of Kolenati!) I have however the opinion that this is not a very wise choice because this name has a very ambiguous history over more than a century of publications. I enclose the article of Dumont (1976) who at the time had settled this difficulty for information.To be continued…

Dumont H.J. 1976Aeschna charpentieri Kolenati, 1846, a synonym of Cordulegaster insignis Schneider, 1845, and on the correct status of Cordulegaster charpentieri auctorum (Anisoptera : Cordulegastridae). – Odonatologica, 5 (4) : 313-321. – [PDF]

C.Deliry (January 19, 2022 – 20h16)

Kalkman V.J. 2022 – On the synonymy of Cordulegaster orientalis Van Pelt, 1994 with Cordulegaster boltonii (Donovan, 1807) (Odonata : Cordulegastridae). – Notulae odonatologicae, 9 (9), 3 juin 2022 : 414-418.

One thought on “About the genus Cordulegaster

Comments are closed.

Comments are closed.