Re: Archaeopteryx not the first bird, is the earliest known (powered) flying dinosaur

[Tim Williams <twilliams_alpha@hotmail.com>]

Gregory S. Paul wrote:

> Gliders are passive aerialists and do not need to updgrade their flight 
> apparatus beyond
> the limits seen in modern exampels, none of which is as well adapted for 
> flight
> as Archaeopteryx much less dromaeosaurs.

The incorporation of the hindlimbs into the flight surface of bats suggests 
that chiropterans began as passive gliders, and then 'upgraded' to powered 
flight.  Pterosaurs (pterosauromorphs) may have done the same.  Modern 
gliders may indeed represent evolutionary cul-de-sacs when it comes to 
powered flight.  Then again, most modern gliders emphasize distance (glide 
path) over maneuverability.  Perhaps microraptorans and pre-archaeopteryx 
fliers (or gliders) used their wings more for maneuverability - to control 
pitch, roll and yaw - than for increasing the horizontal distance travelled.

> The notion that the flightless dromaeosaurs of the Cretaceous were not
> neoflightless descendents of flying dromaeosaurs more advanced than 
> Archaeopteryx is
> highly illogical since, as I explained in detail in DA, they possess a host
> of flight characters more derived than those of Archaeopteryx (and similar 
> to
> those found in modern flightless birds).

I don't want to re-hash this too much, since this dead horse has been 
thoroughly beaten.  But... the fact that these characters ended up as flight 
characters does not necessarily mean that they began as flight characters.  
I read DA cover-to-cover, and I think there is more room for a greater role 
for exaptation in the evolution of the avian flight apparatus.  I also want 
to make it clear that none of my comments are desigend to be personally 
critical of GSP.  I just think that the debate over whether dromaeosaurs 
like _Velociraptor_ were neoflightless is still very much alive.

Cheers

Tim