Rahonavis....Both!

["T. Mike Keesey" <tkeese1@gl.umbc.edu>]

Well, sort of. It's probably an avialan but not an avian. In other words,
it's closer to modern birds than to dromaeosaurids, but outside of the
{_Archaeopteryx_ + Neornithes} clade. Personally, I reserve the word
"bird" for avians, but some extend it to all avialans. "Bird" IS a
vernacular term, after all.

> Was about this time (last year?), that I remember hearing of its
> (Rahonavis`) discovery. Just visited Mike Keesey`s excellent web site, and
> was drawn (no pun intended) to his image of this creature. Mike states that
> it`s somewhere "between" a bird and a Dromaeosaurid. I would`ve thought ,
> (for sure), ...a bird, due to evidence of feather attachment on its wing.
If that's your criterion for something being a bird, then it's a bird.

> But , then again, with all these feathered dinos showing up from China, the
> issue gets kind of fuzzy . (can`t get away from these puns!).
Indeed -- I wonder, if _Caudipteryx_ had been discovered before
_Archaeopteryx_, would it (and oviraptorosaurs and deinonychosaurs) be
considered "birds" today? And would Feduccia, Ruben, etc. still be arguing
for a "thecodontian" origin for this clade (equivalent to Maniraptora)?

> Anyway, what`s the scoop? Can any "claw expert" out there tell me how
> that large pedal claw compares with that of a Dromaeosaur?
AFAIK, it's the same sort of thing. This type of claw seems to spring up
in a lot of other basal paravians -- _Megaraptor_, some enantiornithines,
etc. (and troodontids if they are paravians). And Archie has a
hyperextendable second toe, if not one with a large claw.

> Is there enough evidence besides the claw for a positive link to this
> group?  And,...if I`m correct in suspecting there is, then how can we
> continue comparing Droms with Archie, when there`s a closer
> representative to be had in Rahonavis??
Not sure what you mean... for one thing, _Archaeopteryx_ remains are a lot
better than _Rahonavis_ remains (better than the majority of small
Mesozoic terrestrial animal remains, in fact).

--T. Mike Keesey                                    <tkeese1@gl.umbc.edu>
WORLDS                                  <http://www.gl.umbc.edu/~tkeese1>
THE DINOSAURICON                               <http://dinosaur.umbc.edu>