Talk:Tetradimorpha pterbica

According to the taxobox, this genus belongs to Cryptista, but according to {{Eukaryota}}, it is incertae sedis. I found no source that supports the statement that Tetrahelia belongs to Cryptista with genetic evidence. Alfa-ketosav (talk) 17:04, 31 March 2025 (UTC)

@Alfa-ketosav Precisely. There is no molecular record of Tetrahelia, and it belongs to a class Endohelea that is completely obsolete because it used to include Microheliella maris (the sister group of Cryptista, together forming Pancryptista) as well. It's happened several times that high-rank taxa go obsolete because one genus is suddenly placed elsewhere molecularly and the remaining genera are completely ignored.

The funniest part is that, technically, scientists could easily re-instate Endohelea by making Pancryptista the new Cryptista, therefore including Endohelea within it again. But alas, that's not the consensus. — Snoteleks (talk) 17:48, 31 March 2025 (UTC)

It's a tricky situation, because no paper specifically lists Tetrahelia as incertae sedis eukaryote, everyone simply ignores that Cav-Smith placed it in Cryptista in 2022 at all. Someone in research oughta fix that. — Snoteleks (talk) 17:58, 31 March 2025 (UTC)

Adl et al.'s latest (2019) revision of the eukaryote phylogeny does not list Tetrahelia anywhere, for it was published before Tetrahelia was described, but lists Tetradimorpha as a eukaryote genus of uncertain placement. Alfa-ketosav (talk) 12:21, 1 April 2025 (UTC)

Your reply just led me down a rabbithole. Apparently, Tetradimorpha was listed in 2018 as part of Axomonadida.^[1] Axomonadida, in turn, belonged first to Rhizaria until 2022 when it was moved to Endohelea. In 2022, however, Axomonadida only contains the new genus Tetrahelia, while Tetradimorpha is implied to belong to the order Heliomonadida, which is implied to be part of Rhizaria:

I now think it incorrect to group Heliomorpha with Microheliella (Yabuki et al. 2012) as its kinetocyst extrusomes, long centrioles, and flat centrosomes support its original classification instead in the same order as Tetradimorpha radiata that lacks such channels, i.e., Heliomonadida Cavalier-Smith (1993a), if we accept that Heliomorpha and Microheliella evolved transnuclear cytoplasmic channels for their axopodial axonemes independently, as I now do; this is done in my revised classification of Cercozoa (Cavalier-Smith et al. 2020).

— Thomas Cavalier-Smith, page 514^[2]

But it turns out that this "Cavalier-Smith et al. 2020" does not exist. It is listed as this in the bibliography:

Cavalier-Smith T, Lewis R, Yabuki A, Shiratori T, Oates B, Ishida KI, Bass D (2020) New cercozoan genera Aclada, Acladomonas, Flexomonas, Gazamonas, and Ninjafila, evidence that Discocelia is a cercozoan, and a three-gene phylogeny of Cercozoa. J Eukaryot Microbiol submitted

Meaning there is, somewhere, an unpublished classification of Cercozoa that tells the new position of Tetradimorpha and Heliomonadida. It's sad that it was never published. I'm trying to e-mail the co-authors about it, see if they have any info or if they're planning on publishing something similar. — Snoteleks (talk) 15:16, 1 April 2025 (UTC)

@Alfa-ketosav @Snoteleks I think making Pancryptista contain both Endohelea (containing two genera) and Cryptista is a good idea, because the Yazaki et al., 2022 paper was published before Cavalier-Smith, 2022, and, Cavalier-Smith, 2022 grouped Tetrahelia with Microheliella because Cavalier-Smith says Tetrahelia most resembles Microheliella ultrastructurally, so he used Endohelea to accomodate them. Also, Phanprasert et al., 2025 treats Microheliella as a member of Endohelea, but they don't recognize Pancryptista. I mean, this could count as WP:SYNTH, but, there are a lot more "WP:SYNTHs" in the protist classification of the wiki now, so. Jako96 (talk) 19:01, 20 December 2025 (UTC)

Oh, wait, the CS paper was earlier, my mistake, sorry for the stupid pings. The article itself was published in 2021, and I thought I corrected my earlier self (I earlier thought it was 2021, which is correct). Jako96 (talk) 19:32, 20 December 2025 (UTC)

Still, making Pancryptista contain Endohelea and Cryptista is a good idea, because Cavalier-Smith says Tetrahelia most resembles Microheliella ultrastructurally. Jako96 (talk) 19:34, 20 December 2025 (UTC)