Template talk:Taxonomy/Osteichthyes

Template-protected edit request on 16 January 2023

Change parent to Eugnathostomata, as Teleostomi is obsolete and no longer used. Hemiauchenia (talk) 20:21, 16 January 2023 (UTC)

Question this because the {{Whom}} template is noted in the lede of the Teleostomi article and has gone unanswered since Oct 2022. So an inquiry will be placed on the WikiProject's talk page. P.I. Ellsworth , ed. ^put'r there 04:30, 17 January 2023 (UTC)

Firstly, Telestomi is still used in Fishes of the World (5th edition). This is still the projects's preferred source for the higher classification of fishes, although discussion about changing it to Deepfin often is mooted but never discussed formally. The 5th edition was published after the unsourced edit that claimed it was obsolete. However, FotW5 refers to Teleostomi as a grade so it might be correct that its an obsolete clade even though it's still used a taxon. The lede should be modified so it doesn't imply that Teleostomi is an obsolete grouping, even if some people will argue it should be if not monophyletic.

If we are to change the parent, what source do we use? Deepfin might be suitable for extant fish, but doesn't handle extinct groups like acanthodians. We could just ignore Teleostomi and jump to Eugnathostomata, but how would this affect articles on higher extinct fish taxa? My solution for now is to add |display_parents=4 to the taxobox at Osteichthyes so it shows Eugnathostomata and Vertebrata. A taxobox only showing Teleostomi between Osteichthyes and Chordata is not very helpful. —  Jts1882 | talk  12:38, 17 January 2023 (UTC)

A couple of additional points. (1.) Deepfin's classification doesn't go above Megaclass Osteichthyes (= extant Euteleostomi). (2.) The use of Grade Teleostomi in FotW5 may not be saying it's not monophyletic. It's the acanthodians that are or were thought to form a grade towards Osteichthyes. (3.) The reasoning for it being obsolete may be that it is a redundant with Osteichthyes based on recent findings that all acanthodians may be stem chondrichthyans (Zhu et al, 2013, 2016). We still need a source for the change. —  Jts1882 | talk  13:45, 17 January 2023 (UTC)

And a bit more. According to De Queiroz and Gauthier (1992, p473-5), Osteichthyes is node-based name of the crown clade (of bony fish and tetrapods), while Teleostomi is the stem-based name of a clade consisting of the crown clade plus all extinct taxa more closely related to it than to any other crown clade (i.e. Chondrichthyes (sharks)).

Traditionally, and still in FotW5, the acanthodians are the stem taxa of Osteichthyes. However, the work of Zhu et al (2013, 2016) recovers the acanthodians as stem Chondrichthyes. This would seemingly leave the Osteichthyes without any stem taxa and leave Osteichthyes and Teleostomi as names for the same clade. I assume this is what was meant by obsolete. However, I find it hard to believe that there are absolutely no stem Osteichthyes, when the sister and parent taxa, Chondrichthyes and Gnathostomata, both have large numbers of stem taxa (including all the acanthodians and placoderms). So I think the distinction is still important and we should continue to follow FotW5 until we have new source confirming the position of acanthodians and absence of any stem Osteichthyes. —  Jts1882 | talk  09:06, 18 January 2023 (UTC)

It's not just Zhu's papers. Pretty much every paper published in the last 5 years now accepts acanthodians to be stem-chondrichthyans. E.g [1] [2]. These papers [3] [4] suggest that Ligulalepis, Dialipina, Andreolepis, Lophosteus and possibly the "psarolepids" (Guiyu, Sparalepis, Psarolepis and Achoania) are likely to be stem-osteichthyans. I suppose the real question is here, is what do we do with the Teleostomi article? When I checked the recent usage on scholar, it was solely for papers about modern fish, to which the clade is obviously not greatly relevant. Hemiauchenia (talk) 16:27, 18 January 2023 (UTC)

Whether acanthodians are stem-chondrichthyans or stem-osteichthyans is not the issue. That just determines whether they are included in Teleostomi. The Chen et al (2020) and King (2019) papers show Lophosteus, Andreolepis, Ligulalepis, Dialipina, and the "psarolepids" as stem-osteichthyans. This would make them members of Teleostomi but not crown Osteichthyes. Here, I'm assuming De Queiroz and Gauthier (1992) are right about the stem-based definition of Teleostomi. If Ancanthodii were defined as a node including ancanthodians and crown osteichthyans, then the evidence points to it being non-monophyletic. I haven't found the original definition, but De Queiroz and Gauthier are unlikely to have made a mistake on such matters.

As for the Teleostomi article, it needs updating. The obsolete should be removed as its unsourced (sufficint reason) and likely wrong, given the stem-osteichthyans in the papers you linked. It needs to be pointed out that acanthodians are now considered stem-chondrichthyans which would means they fall outside Teleostomi. Given the long association of acanthodians and Teleostomi it is possible that future workers will stop using the term and then it will eventually become obsolete, but that must be some time in the future. —  Jts1882 | talk  11:06, 19 January 2023 (UTC)