Re: Sharovipteryx - delta-winged glider?

[jrc <jrccea@bellsouth.net>]

I suspect there may have been a seperate, relatively small forewing that was 
not connected to the hindlimb (which could be configured in fairly high 
aspect ratio as well as delta mode).  When in high aspect ratio mode, glide 
ratio would have been quite respectable.  As an aside, a cross-sectional 
mass estimate indicates that Sharovipteryx seems to have weighed about 7.5 
grams, and there doesn't seem to be any solid proof that it wasn't capable 
of flapping (nor proof of flapping either -- that question still seems to be 
open -- I've not seen any analysis of the pertinent articulations or muscle 
attachments and alignments that would either prove or preclude flapping 
flight).  I did some calculations a few years ago, and if it flapped, it 
would have done so at about 15 Hz.  In either scenario, the forewings, if 
they existed, would likely have had more impact on pitch stability than 
control.  You can be pretty sure that primary pitch control was by wing 
sweep.
Jim

----- Original Message ----- 
From: "Tim Williams" <twilliams_alpha@hotmail.com>
To: <dinosaur@usc.edu>
Sent: Tuesday, March 21, 2006 3:18 PM
Subject: Sharovipteryx - delta-winged glider?


> This paper left me a tad confused.  The authors attempt to reconstruct how 
> _Sharovipteryx_ might have glided with only a hindwing slung between the 
> legs and tail; but later on they state that
> _Sharovipteryx_ probably needed some kind of forewing too, in order to 
> balance the large hindwing surface.  If mobile, paired forewings would 
> have vastly improved control during landing and gliding.