Sujet : Re: new fossil find closes 70m year gap in bird evolution
De : rokimoto557 (at) *nospam* gmail.com (RonO)
Groupes : talk.originsDate : 16. Nov 2024, 15:33:19
Autres entêtes
Organisation : A noiseless patient Spider
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On 11/16/2024 5:47 AM, Burkhard wrote:
so the BBC in this article here:
https://www.bbc.co.uk/news/articles/cvg5knlwny4o
I put up the thread on the brain of this fossil.
https://www.sciencedirect.com/science/article/pii/S0960982215009458#fig6My take is that this was a dead end lineage. It may represent an intermediate stage in avian brain evolution, but the lineage represented by extant birds indicates that the modern brain of the birds evolved, possibly 20 million years before this fossil animal lived. The link above is to a 2015 review on avian evolution, and the claim is that multiple lineages survived the extinction event that ended the dinos around 65 million years ago. According to the estimates of this review paper the modern brain structure probably existed 100 million years ago or would have had to evolve by convergent evolution in multiple lineages. The Palaeognathae and Neognathae divergence is placed over 100 million years ago, and these birds would have been fully flight capable with a keel and the modern bird brain structure.
Molecular based divergence estimates usually do seem to over estimate how deep in the past the divergence occurred.
Ron Okimoto