Re: MY THOUGHTS ON THE 'DINO/BIRDS'

[Ronald Orenstein <ornstn@inforamp.net>]

>It was also mentioned that feathers "must have evolved for insulation" 
>(paraphrasing).  From what I have seen so far, the feathers of 
>Protarchaeopteryx and Caudipteryx seem to be for aerodynamics.  They 
>cannot be for steering during cursorial activities (as suggested by 
>Padian 1997) because of the drag involved.  The aerodynamics were 
>probably gliding. 

I find this highly unlikely, and I am not sure on what you base it.  Surely
Caudipteryx at least, with its long legs and shortened forearms (at least
compared to Protarchaeopteryx) seems a most unlikely glider.  I would have
thought the most obvious use for the tail fan at least was display, though
as I
suggested in an earlier post I can imagine (based on no analysis whatever) it
making short, fluttering leaps - again, perhaps, in display.

This highlights one of the bugbears I have argued about repeatedly here - the
assumption that gliding is THE intermediate stage between full powered flight
and flightlessness.  There is no reason for this to be so, especially in a
cursorial form - fluttering as an assist to a leap could, in my view, do just
as well.
--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
1825 Shady Creek Court                 
Mississauga, Ontario, Canada L5L 3W2          mailto:ornstn@inforamp.net