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Re: Lungs and Feathers



GSP wrote:

>elongated than those of most other archosaurs. The posterior ribs heads are
>also double headed and mobile. Both are avian adaptations that allowed the
>posterior ribs to ventilate moderately developed posterior air-sacs. The
>manner in which intercostal muscles operate these ribs has been described by
>Duncker (1971), Fedde (1987) and others. It cannot be overemphasized that
>kiwis simply do not have sternal plates long enough to operate the posterior
>air-sacs, only the ribs can operate them. White admits he is not familiar

and also:

>Am I suggesting sauropods had a bird-like air-sac complex? You bet, and so
>have others. Of course the intensely pneumatic vertebrae confirm the presence
>of air-sacs. The ribcage, especially the rib-head/vertebral articulations, is
>remarkably bird-like. The long mobile abdominal ribs could ventilate the
>posterior air-sacs. This very efficient respiratory system probably evolved
>in order to overcome the dead space inherent to their very long trachea. 

Do you (GSP) or y'all (all others) have any references handy for these
statements?  I'm finally going to have a chance to do some homework, and I'd
appreciate any leads.

  --Toby White