Create a new taxon rank for iNaturalist: the species group

@loarie Is there any chance this feature can/will be implemented in the future? Or should I give up hope?

My understanding is that it’s a lose cause so I’ve been using “complex” to update any insect taxa I run into.

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it’s not a lost cause until staff close the thread and make a statement that this feature will not be implemented. I see no convincing reason why this “feature” shouldn’t be implemented. I personally advise against creating species complex ranks for insect species group taxa you run into.

Here’s a group of hover flies where it looks like we may need a taxon between subgenus and complex: https://www.inaturalist.org/flags/496291
As mentioned we can use “Section” for now but it won’t match what people are used to using for these taxa.

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I think this would be useful for Dialictus bees, a subgenus of about 600 species.

I have a slightly off-topic question about botanical sections. They are not always implemented on iNaturalist even if they are defined elsewhere. Is that more about curator workload or are there guidelines for how big a genus/subgenus should be before adding another layer? Thanks.

Usually if sections have been delineated for a genus but aren’t added to iNaturalist, it’s because no one has asked for them to be added. You can check if there are any active or resolved flags on the taxon to see if they’ve been discussed and decided against, or if curators just haven’t gotten around to adding them yet.

The curator guide essentially recommends to add layers if they will be useful for identification but avoid adding layers just because they exist or for aesthetic reasons.

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Google Scholar search on “species complex”:
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C44&q=“species+complex”&btnG=

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Having just read this thread from start to finish I cannot see the point of a new rank between section and complex.
If subgenera, sections and subsections arleady all exist, then surely there is no need for any “species groups”.
If they dont, then why not just “borrow” sections or subsections for this purpose? Why add yet another layer, unless the existing layers are inadequate?
The argument that some of these ranks have alternative levels in zoology, is not relevant: on iNaturalist they are present in the botanical sense already, and I am not aware of any cases where there being unavailable on iNaturalist has caused an issue.
Botanically for some of the larger Cape genera, we have had to massage the ranks. Not all genera have subgenera-sections-subsections: some have sections-subsections-series (and even subseries): in these cases tweaking the rankings works perfectly.
It would be nice to have some examples, where in spite of using subgenera, sections and subsections there is still a need for another level between subsections and species complexes (which I understand to be for distinct species groups below genus (that do not belong to an existing iNat subgeneric group) where an ID using photographs is not possible). I find it hard to imagine such situations, so some nice examples would be most helpful.
Note: whether species groups are used elsewhere is moot: the issue is do we need a special rank, when we can substitute one of the existing ranks perfectly adequately.

If I remember correctly the iNaturalist staff don’t intend for iNaturalist to become a taxonomy source, but the fact is that because iNaturalist is so actively used and curated, it tends to be more complete and up-to-date than other sources. It’s also many peoples’ most direct access to taxonomy information since it’s where their observations are located, and most people aren’t going to make the extra effort to reference other sources.
If this hasn’t been mentioned above, I think that’s an additional reason to have species groups accurately labelled as such. People (especially in informal settings) are going to reference iNaturalist for taxonomy information and I’d prefer that they be getting accurate information about what rank a taxon is at.

E.g. “I saw this hover fly that’s in section Platycheirus albimanus” when no hover fly specialist would recognize the existence of sections.

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Would exactly the same not apply to species groups? In most cases most specialists will not have heard of them!
I guess it would be too much to expect a specialist to go to the species page and check out the Taxon Framework Relationship (e.g. https://www.inaturalist.org/taxa/922252/taxonomy_details or https://www.inaturalist.org/taxa/64912/taxonomy_details), but technically that is what they should do.

I think this is part of the point, the same would not apply to Species Groups. Species group is a widely used taxonomic rank in the published literature, recognised in many taxa where it is used, as in the example of Platycheirus above - just to pick one of the groups for example https://www.researchgate.net/publication/319312480_A_revision_of_and_key_to_the_Holarctic_and_Oriental_Platycheirus_manicatus_group_species_Diptera_Syrphidae. You can’t read a paper on Platycheirus taxonomy without a discussion of the species groups, and any newly described Platycheirus will be discussed as to which of the species groups it is in. It’s not hard to think of other examples (Merodon Cheilosia and Eumerus in Syrphidae spring to mind immediately for me - a quick Google search led me to this paper on Comptosia (Bombyliidae) - a genus of which I know nothing - which the author divides into 19 species groups - here’s an example from the muscids). Not all of these will be useful to implement, but it is a shame not to have it available as this is terminology that is commonly used by specialists in published literature.

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Perhaps because it’s confusing to see a species group (recognized as such in the zoological literature) being referred to as a section (which is a foreign concept to zoologists). Any rational zoologist’s knee-jerk reaction is to think that it’s an error in need of fixing.

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So you would be ok if shoe was on the other foot and iNat was using species group but not section, forcing plants to be placed at a rank botanists don´t recognise?

Personally, I don´t understand the downsides to this :

  • rank dropdown time : seems like a very minor cost
  • deeper ancestries : the same whether we use section or species group (?)
  • confusing taxon search : the same whether we use section or species group (or complex, etc)

The point re:ancestries only seems to make sense to me if we were to use section AND species group for some taxa… OR, if through the addition of this level it would have a structural impact across the board … - but the latter doesn´t seem to be what loarie implies.
Am I missing something?

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This issue has been on my mind recently, so I’m happy to see some discussion on it already happened. My view is that it would be helpful – for many of the reasons already discussed, and more clear – primarily for the reason that many groups are currently represented using the complex taxon level, technically incorrectly. I obviously don’t know how much stress a new taxon level adds to the site, but I would like to comment on the main aforementioned issue.

This already happens with not only complexes, but also with nominal subgenera, as was said here v

Considering the usefulness of species groups, I don’t see why this should hold them back, and if it really should, perhaps it’d be worth looking into making complexes and nominal subgenera less confusing so it’s no longer an issue. Personally, I don’t even really think it’s an issue. My general way of curating complexes is changing their taxon photos to be different from their nominal species, thus making the icons clearly different when selecting one for an ID. The usage of most of these infrageneric taxa tends to be within the realm of experienced identifiers (this would especially be the case with species groups vs. complexes), who I usually trust to understand the different taxonomic ranks on iNat. At the end of the day it does already say “Complex Myrmecocystus melliger” vs. “Myrmecocystus melliger” and “Genus Myrmecocystus” vs. “Subgenus Myrmecocystus” etc. so I don’t think it’s that confusing once someone is adjusted to the site taxonomy system.

It’s mentioned that groups vs. complexes are often taxonomically unstable, and although that can be true, it definitely is not always. Some genera are really just diverse enough to require a multitude of infrageneric taxa.

I’m tentative to add onto such an old discussion, but I really do think groups should be reconsidered. I don’t see how any of the counterarguments besides potential costs to site maintenance are enough to hold groups back.

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The lack of a “species group” rank continues to cause unnecessary confusion and strife, as one curator after another attempts to “fix” the solutions that other curators have come up with to make do without having this option. Please see @erikvannieukerken’s comment here, and @treichard’s post here about @alberto_colatore’s numerous recent changes to Nepticulidae taxonomy.

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Perhaps two things are needed in this last case.

  1. That new curators get proper training (via online tutorials would be fine) before being let loose on the taxonomy.
  2. A comments tab on the taxonomy page may allow people to discuss issues. At one level add some keys to families and genera pages, but also to discuss why a “malformed” complex was created and what purpose it served, and why the alternatives where not considered. Having to discuss issues on “flags” is often too late, and overzealous curators often commit taxonomic changes without leaving sufficient time for other users to comment.

https://www.inaturalist.org/taxon_swaps/119684

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In this instance I would probably have used Complex rather than Section, as there do not appear to be any subgroups within the group - but it’s a choice of two fudges. One thing that can help is to make ''Stigmella silicis Group" the common name (obviously only helps if you are set to English but other languages could do the equivalent)

That does not, in itself, disqualify a taxon. In the bipaliinae, the Genus Diversibipalium was “erected to include species lacking sufficient morphological information to allow them to be classified in the appropriate genus.” Yet this artificial, dustbin genus does exist on iNat, because it is useful for the worms which are currently in that status – and because it reflects the current state of the literature.

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The rank_level of complex is 11, and the rank_level of subsection is 12. So what will the rank_level of group be? 11.5? This might be why it hasn’t been implemented. But there already are non-integer rank_levels:

  • parvorder: 34.5
  • zoosubsection: 33.5