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Re: Avian Ancestors, new book on theropods



> _Archaeopteryx_ would likely qualify as an avialan under the above
> apomorphy-based definition - especially if one equates "wing" with an
> aerodynamic function.  Its large asymmetrical remiges almost certainly
> had an aerodynamic function (even if that function wasn't necessarily
> powered flight).
> 

I keep reading things like this and to my mind, they make no sense.
Having enough lift for flight almost guarantees that they were used for
just that .... real flight.  From an engineering POV, flight and lift
are a pretty binary things.  As soon as those feather forms developed,
you can be sure that they were used for flight, and powered flight.  Not
gliding, parachuting, catching dragon flies, but full throttle flight.
If anything, one would need to speculate that the powered flight existed 
even before the asymmetrical feather, and the wing.  

Also, FWIW, I'm not sure why there is the belief that the asymmetic
feathers only developed once, in one family lineage.  Is that not
also unlikely?  If there was a lineage of dinosaurs or theropods which
had need of and developed powered flight prior to the asymmetic feather,
then it would make sense that more than one of those lineages then
developed an asymmetric feather.

Ruben