Re: Pterosaurs, and more pterosaurs!

["James R. Cunningham" <jrccea@bellsouth.net>]

Simon M. Clabby wrote:

> They can both be seen at
> 
> http://www.geocities.com/dinowight/istiodactylus.html

I notice that its wingspan is report as being both 5M and 61.5 feet if I
didn't misread it.  What is the actual wingspan?

A quote from the website:

> Pterosaur bones tend to not be cylindrical, but, rather than having a > 
> circular cross-section, they have a triangular cross-section, providing > 
> strength for the thin-walled bones that allow flight.

As stated, this would appear to be structurally incorrect. It is
certainly an overgeneralization.  And, in aircraft terminoligy, the
'triangular' cross section (where it occurs fairly often) is usually
called a D-spar since it resembles a letter 'D' with the flat side
oriented aftward far more than it does a triangle.  In many pterosaur
wings, the D-spar shape does not occur. Quetzalcoatlus is a good example
of that, where portions of the wing that have the D-spar shape in
pteranodontids have either a strap-oval shape or a modified Tee shape.

Minor quibbling aside, its a really nice webpage.

JimC