[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Senter 2006, Confuciusornis, and humeral mobility



Confuciusornis should have had extremely low scapular mobility. The coracoids 
and scapulae are fused (Chiappe et al. 1999) and the coracoids attach to the 
sternum at a wide facet.

Cats should be on the opposite end of the spectrum.

On Mar 22, 2011, at 10:52 PM, Dann Pigdon wrote:

> 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
> _____________________________________________________________
> 

Jason Brougham
Senior Principal Preparator
American Museum of Natural History
jaseb@amnh.org
(212) 496 3544