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Re: Greg Paul is right (again); or "Archie's not a birdy"

David Marjanovic <david.marjanovic@gmx.at> wrote:

> Undulating flight means alternating between fluttering and a purely
> ballistic phase with completely folded wings. Lots of small birds fly that
> way. No gliding in there.

No, you're thinking of bounding flight.  Undulating flight has a glide
phase.  Check out Rayner, JVM (1985). "Bounding and undulating flight
in birds"  J. Theor. Biol. 117: 47-77.  "In undulating flight.... the
animal glides during the rest phase, so that speed is approximately
constant and the flapping phase serves primarily to gain height."

> Too bad that *Volaticotherium* destroys it.

_Volaticotherium_ was certainly an insectivore.  But although we have
no evidence that _Volaticotherium_ gave rise to flapping fliers, we
cannot dismiss the possibility that its descendents employed
undulating flight.