BADD & BCF

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

     It seems like there has been a little bit of coonfusion on the list 
(I know there is for me) regarding exactly what BCF and BADD are.  I have 
personally been debating the bird origins problem from a general cursorial 
vs. arboreal origin perspective, and many or most others I think have 
been doing the same.  However, I am under the impression that BCF 
and BADD do not just mean "trees down" or "ground up" in general, but really 
specific theories on ONE WAY an arboeal archosaur or ONE WAY a cursorial 
archosaur might develop flight.  Just for the record, could someone lay 
out exactly and in detail the specifics of these two theories?   

LN Jeff