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Re: 11th specimen of Archaeopteryx

On Oct 31, 2011, at 1:10 AM, Tim Williams wrote:
> Before we embark on an acronym war, I think I can say we actually
> agree on the major points: A gravity-assisted origin of flight among
> small paravians that were predominantly terrestrial, with trees being
> the platform for aerial launches.  We just disagree on the issue of
> roosting.

Just as a brief reminder when talking about gravity-assisted origins of flight, 
keep in mind that launch from a perch and launch from a terrestrial substrate 
is effectively identical in birds.  Gravitational energy is, of course, useful 
for a gliding trajectory following an arboreal launch. As a result, arboreal 
takeoff is not objectively "easier" than terrestrial launch, per se. This 
distinction is something that I expect both Tim and Don understand quite well, 
but it seems to have been lost on some authors in the literature.  


--Mike H.

Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
(443) 280-0181