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Re: Question on Anchiornis huxleyi
Mike Habib <email@example.com> wrote:
> Joking aside, I think many aspects of that ecotype are going to be
> reasonable tractable to solve in a broadly accurate way, but probably not
> with great precision.
My assumption (or presumption) is that the aerodynamic potential of
these critters (_Archaeopteryx_, _Anchiornis_, _Microraptor_, etc)
will eventually be elucidated - in no small way due to you "flight
mech folks". :-) But even then, the exact ecological or behavioral
function(s) will be far less clear-cut - especially w.r.t. the good
ol' "ground-up" versus "trees-down" thing. In other words, we'll be
fairly confident on the "how", but not so much on the "why".
Mark Pauline <firstname.lastname@example.org> wrote:
> Of course no one is suggesting that Aurornis, Anchiornis, or Xiaotingia are
> ancestral to Avialae or Dromaeosauridae, as all of the recent phylogenies I
> am aware of show these animals evolving after those nodes. You two must just
> mean that they may retain different aspects of that hypothetical ancestor.
Yes, pretty much. For example, _Anchiornis_ has symmetrical remiges,
whereas those of _Archaeopteryx_ and _Microraptor_ are asymmetrical.
But which kind (asymmetrical or symmetrical) was present in their most
recent common ancestor? (This would determines whether the
symmetrical vane of _Anchiornis_ is primitive or a reversal.) Unlike
Matt, I'm not convinced that multiple gains of asymmetry is less
parsimonious than multiple losses of asymmetry. At least as far as
basal paravians are concerned. Modern birds are a whole different