On 11/4/2010 9:14 AM, Mike Habib wrote:
Not to mention that asymmetrical feathers are not actually required for flight, from a first principles standpoint, despite the now popular notion that there must be a 1:1 correspondence.
On Nov 4, 2010, at 7:19 AM, David Marjanovic<david.marjanovic@gmx.at> wrote:
The asymmetrical vanes of the remiges and rectrices of _Archaeopteryx_ suggest some kind of aerial capability. But not necessarily powered flight, because _Microraptor_ has them too.Of course, the only argument against *Microraptor* being a powered flier is the same one that holds for *Archaeopteryx* and *Confuciusornis*: its shoulder joint.However, some flightless birds retain asymmetrical vanes (e.g., flightless grebes)Oho. Reference, please?
The fact that some flightless birds *retain* asymmetrical vanes should not negatively affect the status of asymmetrical vanes as indicators of volancy.