Re: [dinosaur] What is the earliest known bird

On Wed, Apr 28, 2021 at 10:18 PM Mickey Mortimer <mickey_mortimer111@msn.com> wrote:

Based on the previous discussion here by Chen (http://dml.cmnh.org/2021Feb/msg00135.html) on how labile the positions of basal Aves are just based on the inclusion or exclusion of various large flightless forms, I don't think we have a good enough analysis to answer what the earliest avian is.Â If something as complete as vegaviids can move in and out of Aves, what chance do the usual fragments have of being placed with confidence?Â Also of note is that even if we have great evidence a taxon exhibits avian synapomorphies, it could still be on the stem unless we can also tie it to neognaths or palaeognaths.Â That said, I think two pre-Campanian records than deserve more analysis are Turonian Tingmiatornis and Agnolin et al.'s Turonian-Coniacian galliform-like coracoid.

Reference- Agnolin, Novas and Lio, 2006. Neornithine bird coracoid from the Upper Cretaceous of Patagonia. Ameghiniana. 43(1), 245-248.

Mickey Mortimer

From: dinosaur-l-request@mymaillists.usc.edu <dinosaur-l-request@mymaillists.usc.edu> on behalf of David Marjanovic <david.marjanovic@gmx.at>
Sent: Tuesday, April 27, 2021 3:02 PM
To: dinosaur-l@usc.edu <dinosaur-l@usc.edu>
Subject: Re: [dinosaur] What is the earliest known bird
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The oldest member of what is, unfortunately, officially* called Aves is not the late Maastrichtian Vegavis and not the end-Maastrichtian Asteriornis. Most likely it is the presbyornithid stem-anserimorph Teviornis, which is from somewhere low in the Nemegt Formation. That seems to mean it's from the very beginning of the Maastrichtian or older. (For the meaning of "seems", watch this space.) If you read the so-called supplementary information** of the Asteriornis paper, you'll find the authors were aware of Teviornis and didn't even try to argue that it wasn't a member of Aves.

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The latest phylogenetic analyses have found Vegaviidae outside Aves. But if it's inside after all, keep in mind that the oldest known vegaviid is probably not Vegavis (or Polarornis or Neogaeornis, all late Maastrichtian) but Maaqwi, which is end-Campanian (so about the same age as Teviornis).

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*In Phylonyms, the starting point of regulated phylogenetic nomenclature; its registration number is 113. Go here, click on the search result, then click on "Definition".

** Always read the supplementary information. That's particularly important in Nature, Science and PNAS, where the "paper" is just an extended abstract and the "supplementary information" is the actual paper. Asteriornis deservedly came out in Nature.

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Gesendet:ÂDienstag, 27. April 2021 um 21:41 Uhr
Von:Â"Meig Dickson" <mdickso2@uic.edu>

Alternatively, we go the *fun* route and say all members of Pan-Aves are Birds (since they're more bird than anything else), and then, well, there was some sort of avemeta-thing in Poland in the Early Triassic...

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Not that I know of. Are you thinking of the stem-archosauromorph Osmolskina?