cursorial flapping

[Jeffrey Martz <martz@holly.ColoState.EDU>]

     If birds were descended from cursorial archosaurs, flapping would 
probably have preceeded gliding.  A cursorial animal that tried to glide 
would plow a furrow in the ground.  How far can a bird taking off from 
the ground get without flapping?  Are there any modern birds that have 
been seen to pick up enough speed for gliding just by running?   
     Archaeoptyeryx probably wasn't that 
strong a flapper.  The glenoid fossa wasn't nearly as dorsally directed as 
in modern birds, the wrist wasn't as well stabilized, and the pectoralis 
muscles were much smaller.  Might this be taken as evidence of a 
gliding, and hence arboreal origin?  
    
LN Jeff