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Re: Vegavis gen. nov. - new anseriform in today's Nature
It's true that they refute Feduccia's extreme version. Fossil evidence
diversification of Neoaves in the K is however still lacking, as the
In 1996 at least, Feduccia thought that the crown-groups of Palaeognathae
and Neognathae were entirely Cenozoic. (Can't live with a Cretaceous duck.)
A less extreme version is the idea that only the crown-group of Neoaves, or
only those of, say, Metaves and Coronaves, are Cenozoic-only. (Can live with
K ducks, but not with K parrots.) The opposite is what the molecular
divergence date estimates of the last 10 years say: that most if not all
divergences between the extant bird "orders" happened in the Cretaceous.
(Requires both K ducks and K parrots.)
Birds should have been affected as badly as non-avian dinosaurs.
Why do you think so? Most birds have advantages on their side that most
other dinosaurs lacked:
- Small size. Means, large populations, low food requirements, easier to
- Flight. Means the ability to cheaply cover vast distances in search of
food, mates, nesting sites and whatnot. This in turn means that much fewer
individuals per continent need to survive to continue the species.
- Ability to live off seeds (Galliformes, Palaeognathae).
- Ability to live off insects (Galliformes, Palaeognathae, who knows what
- Being part of ecosystems that aren't based on living plant parts
(especially in freshwater; Anseriformes, whatever).
The more species we find that are ancestral to extant species, the
less support there is for an instantaneous, all-encompassing catastrophe.
Evidence for Cretaceous members of Neoaves -- a huge clade! -- is still
quite poor. Besides... the more species we find that are _not_ ancestral to
extant species, the _more_ support there is for an instantaneous,
all-encompassing catastrophe... and this, too, is going on now, partly by
new finds (the toothed bird of Maastricht, *Limenavis*...), partly by
revisions of known specimens (*Iaceornis*, probably *Polarornis* and