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Re: Avian Monophyly (Was Re: Sheesh)... :-)



Evelyn Sobielski wrote:

The "Birds Came First" model in a nutshell.

No!!! Yikes!!! What I mentioned was a phylogenetic hypothesis under which powered flight is primitive for Paraves, or for some other subset of Maniraptora more inclusive than Aves. This is not "BCF" (sensu Olshevsky), which is far more radical.


BCF ("Birds Came First") proposes that ALL dinosaurs evolved directly from arboreal ancestors - not just maniraptorans, but all theropods, and sauropodomorphs and ornithschians too. Crazy talk. BCF is Greg Paul's "Dinosaurs of the Air" on crack.

after which time there seems to have been some secondary flightlessness but very few new takes on powered flight (of which Rahonavis IMHO was one, hence its primitive features.

Rather than this convoluted scenario, I still don't see why _Rahonavis_ couldn't just be considered a relict taxon. After all, there were long-bony-tailed birds around in the Early Cretaceous.


BCF is a feasible argument on basis of the available data,

No, BCF is nonsense. It is a "just-so" story that has absolutely no supporting evidence. Worse, because it's so vague and poorly constructed, BCF does not qualify as a hypothesis. Thus, BCF cannot be tested, and so it cannot be refuted. To borrow a quote from Wolfgang Pauli, "It is not even wrong".


Cheers

Tim

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