Talk:Protist classification

Great modification of this article

Hello, I am slowly but steadily improving this article by updating the outdated taxonomy and correcting mistakes, as well as making things less confusing and overwhelming by adding some bits of explanations, images and, most importantly, adding bibliography, which was almost nonexistent beforehand. If anyone has any questions, doubts or suggestions about this feel free to answer this message! Snoteleks (talk) 11:29, 10 August 2022 (UTC)

Announcement of March 2023

Hello, for the past weeks I have been remaking this page to be as accurate as possible according to the newest classification by Adl et al. (2019), which finally rejects traditional paraphyletic taxa in favour of clear-cut cladistic definitions. I finally posted my edit today, which brought 100% of the info on that classification. However, there are still a couple things that need to be taken care of, in order to make this page as complete as possible:

1. Complete the list of genera for ciliates, ochrophytes, foraminifera and dinoflagellates. The study by Adl et al. does not include all the genera of these big groups, so this needs to be completed independently.
2. Fix disambiguation links to names of genera. A lot of genera haven't been given their own page yet, and overlap instead with the names of different pages.
3. Update the page according to studies from 2019 to 2023 and so on. Many new changes to lower classifications have been made, including the revision of some taxa and the creation of others. This should be reflected in the page, as it is meant to be the nexus for all pages that include some level of protist classification.

Any help is useful and welcome, like in any Wikipedia article, but remember, always cite sources for your additions and changes. I cannot stress this enough, because when I began modifying this page it was absolutely sourceless! ☽ Snoteleks ☾ 08:33, 3 March 2023 (UTC) ☽ Snoteleks ☾ 08:33, 3 March 2023 (UTC)

References

Kingdom Chromista - needs more discussion in the article?

Not sure how this might best be included, but possibly worthy of note that as an alternative to the Adl et al. treatment set out here, Catalogue of Life (CoL), WoRMS, AlgaeBase and elsewhere use kingdoms Protozoa and Chromista in place of Protista at this time, following the treatment of Ruggiero et al., 2015 and later works by Cavalier-Smith in particular. See e.g. https://www.catalogueoflife.org/data/taxon/C and https://www.catalogueoflife.org/data/taxon/Z . I do the same in my own database (IRMNG), principally to maintain congruence with CoL/WoRMS at this time; when or if they change, I shall do the same... Tony 1212 (talk) 23:26, 15 February 2024 (UTC)

Also noting, kingdom Chromista currently treated as valid in ITIS (https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=630578) and GBIF (https://www.gbif.org/species/4). NCBI taxonomy, by contrast, does not include it (example: https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=2985 for Ochromonas). A matter of taste perhaps, but its current pervasiveness should possibly be documented here... Tony 1212 (talk) 00:14, 16 February 2024 (UTC)

PS I currently supply around 5,600 generic names from my database to CoL (see https://www.catalogueoflife.org/data/dataset/2007), mainly in Chromista, Protozoa, and "plant algae", which is a practical reason for my compilation to remain "in step" with their current treatment(s) at any particular time :) Tony 1212 (talk) 00:19, 16 February 2024 (UTC)

@Tony 1212 I completely agree. I've been meaning to include a section of the traditional classifications that delves deeper into the Protozoa-Chromista configuration. It would be nice for readers to have the complete context. My idea was to make this into a section before the "Current classification" section. I would also like to update the Cavalier-Smith's system of classification page according to his 2017-2018-2022 papers, which seem to be the last peer-reviewed traces of this traditional system. —Snoteleks (Talk) 06:55, 16 February 2024 (UTC)

Euglenids

Just to remind myself, there is starting to be a phylogenetic taxonomy of euglenids, despite what the note says. I will add that soon, I have already found enough references. —Snoteleks (Talk) 07:37, 16 February 2024 (UTC)

Ochrophyta: Instability of the position of Eustigmatophyceae

(@User:Snoteleks) Results of phylogenomic analyses from 2024 show the instability of the position of Eustigmatophyceae among ochrophytes. When plastid genes are used, there is evidence for eustigmatophytes being nested within the SII clade, specifically related to Chrysophyceae and Synchromophyceae /Picophagea (e.g. or the preprint , to have recent references from 2022). Analyses of nuclear genes however tend to favor eustigmatophytes being a sister lineage of the SI clade (preprint ).

After adding new transcriptomes to an existing phylogenomic dataset and updating the dataset to represent 14 out of 17 major ochrophyte classes including Olisthodiscophyceae, Phaeothamniophyceae, Schizocladiophyceae, and Picophagea, a robust grouping of Eustigmatophyceae with Raphidophyceae-Phaeophyceae-Xanthophyceae (SI clade) was recovered in a study ( issued in September 2024) by another group of scientists.

I propose to take the class Eustigmatophyceae out of Limnistia and raise it to the same level as SI and SII clades until the position is finally clarified. (It would be strange to have it in a group named "clade" SII which then may be polyphyletic!) Petr Karel (talk) 15:58, 16 December 2024 (UTC)

Petr, I made one small edit to this article 6 years ago (fixing a wikilink). Chiswick Chap (talk) 16:04, 16 December 2024 (UTC)

I am sorry, I wanted to ping the item to User:Snoteleks. Petr Karel (talk) 16:33, 16 December 2024 (UTC)

@Petr Karel Hi, thank you for pointing that out! Can you link to the analysis? — Snoteleks (talk) 19:46, 16 December 2024 (UTC)

My bad @Petr Karel, I was reading this talk page from my phone and none of the links showed up. Now on my desktop I'll get to reading. — Snoteleks (talk) 21:35, 16 December 2024 (UTC)

Potential rearrangement of sections

I think that hierarchical sections according to taxonomy get very convoluted and overly complex when it comes to protists, since there's so many clade names. Perhaps we could simplify the sections in the article like this, avoiding higher clades:

• Overview (with explanation of higher clades)
• Amorphea
  • Amoebozoa
  • Obazoa
• Archaeplastida
• Cryptista
• Haptista
• SAR
  • Stramenopiles
  • Alveolata
  • Rhizaria
• Excavates
  • Discoba
  • Malawimonadida
  • Metamonada
• Orphan groups
  • Ancyromonadida
  • CRuMs
  • Hemimastigophora
  • Provora
  • Telonemia
• Genera of uncertain affiliation

— Snoteleks (talk) 22:05, 5 April 2025 (UTC)

This also might be a good way to delve into older classifications, although I'd prefer having that over at the Protistology article. — Snoteleks (talk) 16:59, 5 May 2025 (UTC)

New direction ongoing, new title suggested

After reading up on @Esculenta's wonderful new GAN Lichen systematics, I've realized that the title of this article is inadequate, and it would be better if it was something like "Protist classification". Based on this, I have discarded the idea of writing about the history of protist classifications, as this is better suited for a new article mirroring Esculenta's (named "Protist systematics"). However, this frees up the present article to fully delve into the details of protist classification and diversity as it is now, without worrying about historical background.

Moreover, I've taken inspiration from the literature and decided that the current format of the article can be improved for the average reader. Instead of a simple and endless bulky list of taxa, I've decided to ditch treating the section headings themselves as part of the list, and begin treating them as chapters, inside of which a single taxonomic list is housed. This will also be accompanied by a brief description of the higher taxon's (i.e., the name of the chapter) composition and diversity, as well as which authors or works are important for its classification. I have done trials of this format with Euglenozoa and Heterolobosea, and they looked satisfying so I added them already.

This also has the advantage of not having to wikilink the section headers or disclosing their authorities and years of publication, which, frankly, is unappealing.

An "Overview" section will remain, as it is especially important to explain the higher clades so that they do not need to be part of the section headers. Phyla are the important categories, so they should get their own sections, as well as the most recognizable supergroups, but always keeping the maximum number of section levels to 3 (as it is very hard to distinguish further subsections from each other as a reader). Very minor clades, particularly non-phyla (such as Tsukubamonas) do not need their own sections, as they can be explained in the their parent taxa's sections (Discoba, in the case of Tsukubamonas). That way, I envision a sectioning like this:

• Overview of classification
• Amorphea
  • Amoebozoa
  • Obazoa
• Archaeplastida
  • Rhodophyta
  • Rhodelphidia
  • Picozoa
  • Glaucophyta
  • Green algae
    • Prasinodermophyta
    • Chlorophyta
    • Streptophyta
• Cryptista
• Haptista
• Alveolata (incl. explanation of colponemids)
  • Ciliophora
  • Myzozoa (incl. explanation of Squirmidea)
    • Chromerida
    • Apicomplexa
    • Perkinsozoa
    • Dinoflagellata
• Rhizaria
  • Cercozoa
  • Endomyxa
  • Retaria (still unsure of whether this intermediate would be necessary)
    • Radiolaria
    • Foraminifera
• Stramenopiles (incl. explanation of Platysulcus)
  • Bigyra
  • Pseudofungi
  • Bigyromonada
  • Ochrophyta
    • Diatoms (need their own section due to volume and incongruent modern classification)
• Excavates
  • Malawimonada
  • Metamonada
  • Discoba (incl. explanation of Tsukubamonas and Eolouka)
    • Jakobida (still debating if they need their own section)
    • Heterolobosea (finished)
    • Euglenozoa (finished)
• Minor clades
  • Ancyromonadida
  • CRuMs
  • Hemimastigophora
  • Provora
  • Telonemia
• Protists of uncertain position

This is something I will try to be updating (slowly, due to the volume). Meanwhile I will take this chance to keep introducing taxon ranks where they are missing, as well as checking for mistakes. — Snoteleks (talk) 00:45, 28 July 2025 (UTC)

Btw, I'm doing trials of the new format at this test page. — Snoteleks (talk) 00:48, 28 July 2025 (UTC)

P.S. I also think adding the authority of each genus is a tremendous waste of time and an unrealistic goal, not to mention probably unappealing to the average reader, so I'm also going to stop that. — Snoteleks (talk) 15:31, 28 July 2025 (UTC)

Abandoning lists in favour of tables without authorities

Since this discussion about the inclusion of authorities in lists, I realized that the size of this article makes it hard to read for others. I have been experimenting in a test page with a new format that relies on collapsible tables instead (thanks to the visual editor for making this process much easier). As the editor that added virtually all of the present text, I think I have enough "authority" (ha) to implement this new style onto this page myself, but I know it's quite radical and prefer to gather support for it first.

The main benefits of this style are:

• Easier navigation thanks to collapsible tables
• Less vertical expansion, as parent taxa are seamlessly integrated in merged cells
• Simplification through the erasure of some intermediary clades, for example Conosa, Cadamassta, SI/SII/SIII, etc.

Comment: I personally see this as a positive, as the massive scope of the page calls for simplification. If a reader is interested in the particular phylogenetics of Parabasalia or Ochrophyta, they can just click their corresponding articles. Higher clades can be summarized in each section's introductory paragraphs.

• Easier to avoid hierarchy mistakes, as the number of bullets is sometimes hard to keep track of (even in Adl et al. they struggle with this).

The main drawbacks of this style are (so far):

• No taxonomic authorities, therefore the text information may be considered poorer.

Comment: I still don't entirely agree given that genera lack authorities in either style, but other editors have said this.

• No synonyms for taxa above genus, therefore some useful context may be missing for readers, especially for when there are two names for each code of nomenclature.

Comment: I don't think all synonyms are necessary, so this issue could be solved with footnotes.

• Tables look "undone" if not all genera/families are filled in, which is the case as the article currently stands.

I invite you all to check out the test page and let me know what you think. It's still a work in progress but most groups are covered. Mainly Alveolata is still not done. — Snoteleks (talk) 21:01, 26 July 2026 (UTC)

Pinging some people that were participating in the initial discussion: @Kweetal nl:, @Ethmostigmus:, @Plantdrew: — Snoteleks (talk) 21:07, 26 July 2026 (UTC)

We read from left to right. There is a lot of empty space in the left side of the table. Wouldn't it be better use of space if you vertically flip the hierarchy and started lefthand side with low-level taxa (i.e., with genera). I'd also prefer the genera lists as vertical lists instead of horizontal comma-separated lists (and with 'authority, year' but maybe that decision has already been made). - Kweetal nl (talk) 03:03, 27 July 2026 (UTC)

@Kweetal nl Regarding the absence of genus authorities, I was inclined to include them, but I thought it would take up too much space. Also adding authorities to the huge number of genera would delay its completion significantly, although I would not mind it. — Snoteleks (talk) 10:20, 27 July 2026 (UTC)

A few comments:

• The table is clean and looks good on a desktop or laptop, but what about mobiles? Tables are unresponsive and there is a trend to avoid them. The lists read more easily on mobiles and would be even easier if synonyms and authorities were removed like in the table. Perhaps including synonyms and authorities and list v table should be different questions. I'm not against the table but the impact on mobiles should be considered.
• Synonyms should be included when the names are from different codes.
• I don't find the collapsible element on the whole table particularly useful. It would be more useful placed on the taxa on whole rows (e.g. class in Amoebozoa, subphylum in Cercozoa, phylum in Pseudofungi).

 —  Jts1882 | talk  09:12, 27 July 2026 (UTC)

I %100 agree with the last bullet. Jako96 (talk) 09:41, 27 July 2026 (UTC)

@Jts1882 @Kweetal nl Very good points. I'm pretty novice when it comes to HTML syntax but I will try to find a different style with more verticality (that way synonyms can fit, and there is not as much empty space in the lefthand side) and collapsible sections within the table. — Snoteleks (talk) 10:02, 27 July 2026 (UTC)

Lists are already vertical, I think they are alright, if you ask me. Jako96 (talk) 10:22, 27 July 2026 (UTC)

The issue pointed out by Ethmostigmus could simply be solved by including the monotypic subclass and the only order in different lines instead of including them within the same line. For example:

• Subclass Ventricleftia Cavalier-Smith in Cavalier-Smith, Chao & Lewis 2018
  • Order Ventricleftida Cavalier-Smith in Howe et al. 2011

Jako96 (talk) 10:35, 27 July 2026 (UTC)

I strongly think that unranked clades should definitely be included. It would be hilarious that such a large list not including those somewhat important groups (also, why is the superorder Euglyphia not shown for example?). Also, ranks should be used as only in the sources, so Euglenophyceae can't be a subclass, Hexamitinae and Giardiinae are subfamilies instead of suborders, etc. And, is there a source that uses order Pansomonadida with a subclass Pediglissa and class Sarcomonadea, or a source that uses Pluriformea as a monotypic class and uses the order Corallochytrida under it? There is not, and I think that different taxonomies should not be mixed. Jako96 (talk) 10:29, 27 July 2026 (UTC)

Using Euglenida and Ploeotiida is another example of such WP:SYNTH assignments. Jako96 (talk) 10:58, 27 July 2026 (UTC)

I think the table format is an improvement over the current version of this page. Plantdrew (talk) 19:20, 27 July 2026 (UTC)

Me too! The only issue left is adapting it to mobile. I think that ignoring authorities is definitely a step in the right direction due to the massive size of the page. If it were the specific taxon article, then I would for sure include them. — Snoteleks (talk) 20:18, 27 July 2026 (UTC)

@Jts1882 @Kweetal nl I came up with a new style that is quite time-consuming, but let me know if it looks closer to what you'd want (the link is here). Keep in mind I only included a couple of taxa to show what it would look like. It displays well on mobile, and has columns for genera on desktop. — Snoteleks (talk) 19:41, 27 July 2026 (UTC)

I do like the first Amoebozoa table, the one with the authorities. Nice! I'd probably reduce the number of genera columns from 3 to 1 but that's a minor thing. ---- Kweetal nl (talk) 06:02, 28 July 2026 (UTC)