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Re: Senter 2006, Confuciusornis, and humeral mobility

On Wed, Mar 23rd, 2011 at 1:39 PM, Jason Brougham <jaseb@amnh.org> wrote:

> On the subject of humeral mobility and powered flight, is it possible that
> the first stages of flapping could involve flapping the wings downwards
> only?
> In other words, on the lineage leading from a glider to a powered flier,
> could the early stages involve gaining lift and extending glides by
> flapping the arms from horizontal ventrally down to meet at the midline?
> Then, in later stages of refinement, the recovery stroke could be added by
> more complex shoulder modifications?

Also; how mobile where early bird scapulae? A more mobile scapula system might 
have allowed 
the forelimbs to lift slightly above horizontal, even if the shoulder socket 
itself was more restrictive. 
I'm thinking of the incredibly mobile scapulae that cats have, which seem to 
increase the range of 
motion of the forelimbs significantly.


Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj