Talk:Diapsid

I think the description here should be a little clearer. It repeatedly refers to diapsids being characterised by having two openings on either side of the skull, and yet every picture shows a skull with four openings. I assume this means in addition to an eye and a nostril, but as it's written now that's far from clear. While in scientific literature one could assume the reader understands this, in an encyclopaedia I think it should be explained. 76.118.92.242 (talk) 18:37, 21 May 2014 (UTC)

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Recent phylogenetic analyses have rendered Diapsida paraphyletic and invalid (Simoes et al, 2022; Buffa et al. 2024; Jenkins et al. 2025). The official definition of this clade is "the clade characterized by the apomorphy ‘upper and lower temporal fenestrae' as inherited by Sphenodon" (See Gauthier and the phylocode), therefore excluding araeoscelidians and rendering this clade paraphyletic or equivelent with Neodiapsida.

However, Neodiapsida is very much a real clade and should have its own page. Furthermore, the late Permian neodiapsida have huge utility for discussions on modern reptile origins, extending this discussion down to unrelated Carboniferous araeoscelidians makes this page quite the head spinner.

I'd suggest making this page for Diapsida as a skull fenestration scheme as it was originally intended by Obsorn (1903) and later studies. A history of the name 'Diapsida' being applied to true taxonomic groups (rather than purely classification schemes) can be discussed, ending on the fact that this clade is no longer supported in modern analysis. Discussion of Neodiapsida can be removed over to a Neodiapsida page. As it stands, this page jumps back and fourth from discussing Diapsida and Neodiapsida, where they both deserve their own pages Drfossilphd (talk) 20:39, 28 August 2025 (UTC)

If you're willing to actually put in the work to make half-decent proposed Diapsid (skull fenestration scheme) and Neodiapsida articles, then I think we can potentially discuss this. As is, unless someone is willing to put in work to actually write these articles, I don't think splitting out Neodiapsida is viable. Also, given the major upheval is ongoing and will take years to settle, it's important that Wikipedia is conservative and doesn't jump the gun on the issue. Hemiauchenia (talk) 20:52, 28 August 2025 (UTC)

I agree Drfossilphd Chanchu0518 (talk) 11:50, 29 August 2025 (UTC)

This is a real hard nut to crack. On one hand, I think I lean towards supporting a split for Neodiapsida. If we have papers using it as a clade in models where Diapsida doesn't even exist I don't think it's reasonable to redirect it here and treat it strictly as a subclade. I do worry splitting out reptile taxonomy over more underwritten articles will only obfuscate clear communication, but I don't think that kind of practical argument should override taxonomic honesty. As for the suggestion we deprecate Diapsida, I don't think I can support that. While tides are shifting, it seems incredibly non-neutral to go all in on a selection of recent papers and treat them as the new skeleton of our page structure. Until it becomes the new literature default it's WP:TOO SOON, though it obviously deserves significant coverage across all relevant articles. But of course trying to clearly and fairly convey both more traditional models and one where Diapsida doesn't even exist is going to be a nightmare. One way or another I think splitting Neodiapsida is the first step to take. LittleLazyLass (Talk | Contributions) 16:56, 29 August 2025 (UTC)

Pinging original merge discussion paritipants who have not already participated: @Trilletrollet:, @SilverTiger12: & @Xiphactinus88:. Hemiauchenia (talk) 18:11, 29 August 2025 (UTC)

I don't think we should deprecate Diapsida yet. There is an upcoming paper by Marjanović that treats Diapsida as a monophyletic group excluding araeoscelidians (which fits the Phylocode definition quoted above), so we don't know if Diapsida will become an obsolete taxon like Anapsida, or if it will just be viewed as a senior synonym of Neodiapsida. Or maybe both at the same time? Until that is cleared up, the current system works fine I think. —Trilletrollet [ Talk | Contribs ] 19:18, 29 August 2025 (UTC)

I noticed the temporal fenestra page is pretty short, maybe we could expand it with an in-depth section about diapsid skulls? Then we wouldn't need separate articles for the skull type and the taxon. —Trilletrollet [ Talk | Contribs ] 19:40, 29 August 2025 (UTC)

diapsida to the exclusion of araeoscelidia would be synonymous to neodiapsida. OldCambrianHag (talk) 13:33, 30 January 2026 (UTC)

@Drfossilphd Based on the information you gave here, I 100% support the diffusion of Neodiapsida into its own article. — Snoteleks (talk) 21:06, 29 August 2025 (UTC)

That would be nice, if I am being honest. We could also update the articles of every sauropsid that was historically deemed a "parareptile". CoralReaper (talk) 12:00, 3 October 2025 (UTC)

diapsida to the exclusion of araeoscelidia would be synonymous to neodiapsida.

and yes, we absolutely need to fix all the wikipedia pages that treat "parareptilia" and "eureptilia" as real clades, they are thoroughly outdated. OldCambrianHag (talk) 13:32, 30 January 2026 (UTC)

Diapsida technically can never be "paraphyletic and invalid" because (as is mentioned in this page) it is defined as "the most recent common ancestor of araeoscelidians, lepidosaurs, and archosaurs, and all its descendants", meaning the new phylogeny expands Diapsida by including anapsids (and sometimes synapsids) in it. We must now have Diapsida as Amniota's parent taxon (Simões et al., 2022) or as a group that includes parareptiles (Buffa et al., 2024; Jenkins et al., 2025)... This also applies to Parareptilia (now including Neodiapsida) and Eureptilia (the latter becomes the araeoscelid+captorhinid clade in Simões et al.). Kiwi Rex (talk) 00:18, 8 March 2026 (UTC)

that defines these clades in an extremely confusing way tho, where its better to just not use them anymore. diapsida implcity implies that two temporal fenestrae is a homologous character across all its descendants, when it is not. eureptilia would now include synapsids, parareptilia would now include every sauropsid except araeoscelidians, and diapsida would be synonymous with sauropsida (with sauropsida being the less confusing and more accurate name).

ftr i'm going off of jenkins et al here and assuming araeoscelidians = basal sauropsids and captorhinids = a sister taxon to synapsida+sauropsida clade. OldCambrianHag (talk) 19:35, 8 March 2026 (UTC)

calling sauropsida "diapsida" would imply its defined by a character that it actually is not defined by (the ancestors of the "parareptile" groups never had an upper temporal fenestra) OldCambrianHag (talk) 19:36, 8 March 2026 (UTC)

the UTF in petrolacosaurus is nonhomologous to that in neodiapsids, its not a shared character its independently derived OldCambrianHag (talk) 19:37, 8 March 2026 (UTC)

Many vertebrate palaeontologists oppose apomorphy-based clades though, so even taxa named after apomorphies (like Diapsida) end up becoming technically impossible to turn obsolete because there will always be a last common ancestor of [whatever1] and [whatever2]. It is what it is... Kiwi Rex (talk) 21:55, 9 March 2026 (UTC)

i think sauropsida should be retained over diapsida since it is in more common use and more accurate. OldCambrianHag (talk) 23:15, 9 March 2026 (UTC)

the jenkins topology would render the two synonyms. OldCambrianHag (talk) 23:16, 9 March 2026 (UTC)