Re: Rahonavis....a Bird?....a Dino?

["John V Jackson" <jjackson@interalpha.co.uk>]

What is the preferred orthodox BAMM view on the relationships between
Rahonavis/Archaeopteryx/droms?:

1)  Neither of the two flying forms is descended from the other, so either
flight must have evolved twice or they must have descended from a flying
common ancestor.  The latter would make the similarity between Rahonavis and
droms difficult to reconcile with BAMM.

2)  Rahonavis is descended from Archaeopteryx;  this would make the
similarity between Rahonavis and droms difficult to reconcile with BAMM.

3)  Archaeopteryx is descended from Rahonavis.  This must be the BAMM
favourite.  As it happens, the crucial wing/shoulder/and maybe even uncinate
parts that would probably have shown Rahonavis to be a more advanced flier
than Archaeopteryx were not found.  But if Rahonavis were shown to be a more
advanced flier than Archaeopteryx, say if a better Rahonavis skeleton were
found, what would be the BAMM view?  In fact, is there anything in what we
have of Rahonavis that suggests it is a more advanced flier?  Does anyone
consider Rahonavis to have been flightless (and without a flying ancestor)?


JJ


http://www.geocities.com/CapeCanaveral/Hall/2099/DinoKabin.html