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Re: the supracoracoideus system and bird flight



    In summary, I still maintain that if
>   Archaeopteryx could fly at all, it was a lousy flier. It had
>   precisely the worst possible kind of tail for flight (Spearman) -
>   the worst shape, with feathers mounted on a long bony tail. It did
>   not have the supracoracoideus that other flying birds need for good
>   take-off and safe landing. It did not have the box-like pelvis that
>   makes a sound undercarriage - again for the shock of landing. It did
>   not have the long primary feathers at the ends of the wing that are
>   needed for best lift: instead, it retained the vicious little claws
>   of its theropod ancestors.  It did not have the flexible wishbone
>   that helps to give the repeated rhythmic wingbeat in today's flying
>   birds: instead, its furcula is thick and rigid.  One in seven
>   specimens has a very thin sternum, which if anything argues for the
>   kind of pre-flight flapping that Lipps and I associate with display,
>   and Padian associates with powerful predatory strikes - rather than
>   full flight.  And we (or at least I) still don't have a very clear
>   picture of the morphology of the sternum on specimen 7.


     An early flyer is bound to be a crappy one.  Its my impression that 
all the characteristics that made Archaeopteryx a bad flier are primitive 
characteristics, not characteristics that might have evolved for a 
specific lifestyle other than flight.  Archaeopteryx may simply have not 
been in the flying business long enough to have find tuned its anatomy.  Why 
would an early  bird using its feathers for soemthing other than flight be 
motivated to evolve IMPROVEMENTS on flight capacity like the block-like 
pelvis, flexible wishbone, longer primaries, pygostyle, and thick  sternum?  


LN Jeff