Re: Archaeopteryx flight

[NJPharris@aol.com]

In a message dated 9/3/01 12:18:59 PM Eastern Daylight Time, 
david.marjanovic@gmx.at writes:

> Indeed he thinks (or thought in 1988) that *Archaeopteryx* had a similar
>  locomotory repertoire to young hoatzins. I think that climbing is largely
>  ruled out, however. Flying may have been impossible according to the old
>  feather-asymmetry paper the citation of which I just cited :-) .
>  "surely much less bound to swimming than Archie"? :-)

I think this quote from HP Jim Cunningham 
(http://www.cmnh.org/fun/dinosaur-archive/1999Oct/msg00018.html) is worth 
taking a look at here:

"A question to all.   Where did this concept first originate?  Symmetrical
feathers are perfectly capable of generating as much lift as an
asymmetrical feather.  They just require a bit more mass in the shaft
(and/or a larger shaft diameter) to resist the torsional pitching moments
generated about the symmetrically located shaft.  The extra weight
required in the shaft of the symmetrical feather isn't enough to affect
the flight mechanics or power required to fly, but might well be enough to
substantially impact the biological cost of the molt, which may have been
related to the eventual development of the asymmetrical flight feather.
However, don't expect the first flying birds to have asymmetrical feathers
(though they may have), and I'd recommend against rejecting any
possibility of flight in an animal simply because it lacks asymmetrical
feathers.  Asymmetric feathers are not a prerequisite for either the
trees-down or ground-up scenario, or any other hypothesis of flight
origins that I'm aware of."

--Nick P.