Re: Conway's Nyctosaurus Restoration

[David Peters <davidrpeters@earthlink.net>]

My confusion comes from looking at Bennett's Fig. 6, which shows KJ1 with a
superior ramus roughly 75 cm long and a posterior ramus roughly 15 cm long (5:1
ratio), while KJ2 sports a shorter superior ramus, roughly 60 cm long and a 
longer
posterior ramus, roughly 30 cm long (2:1 ratio).

Are the shorter rami considered broken?

All for naught, I suppose, if no membrane exists.

David Peters
St. Louis



"James R. Cunningham" wrote:

> David Peters wrote:
> >
> > Age or size aside, the proportions appear to be different. Different shaped
> > airplane wings give different performance characteristics, so perhaps the 
> > same
> > can be said here.
> >
> > dp
>
> Chris Collinson's take was correct.  I enclose underneath the dashed
> line below the text of an earlier response from a few minutes ago that I
> sent directly to Dave, but forgot to copy to the list.  Colin has
> checked his drawing, and the relative dimensions match within 2-3%, well
> within normal variation between individuals.  As an aside, it's not
> unusual for long bone dimensions to vary by up to about 5% between the
> left and right sides of a single individual.  Variations between
> different individuals can be considerably more without substantially
> affecting performance.  I set the preliminary computer model up to
> handle either KJ1 or KJ2, or any other pterosaur of roughly similar
> configuration.  I haven't sent the KJ2 numbers to John, Colin, or
> Margot, because they aren't different enough to matter. If Nyctosaurus'
> bony crest supported a membrane, then the sail for any similarly
> configured individual was squarely within the operational range required
> for the thing to function appropriately.  Different shaped airplane
> wings do indeed give different performance characteristics -- but
> similarly shaped airplane wings give similar performance, and that is
> the case here as well.
> All the best,
> JimC
>
> -------------------------------------
>
> > David Peters wrote:
> > >
> > > of the proposed sail. Does the smaller chord, taller mast change the
> > > equation? Or visa versa?
> >
> > No, not particularly.  KJ2 is just a larger specimen than KJ1.  long
> > bone ratios are slightly different, but within the normal variation
> > between individuals of nearly the same size.  That said, we will check
> > for a mistake -- and appreciate the heads up.  Both images were prepared
> > from Chris' photos of each.
> >
> > > Or ~ is one reconstructed in error? Perhaps one should match the other
> > > better?
> >
> > Off the top of my head, I think it is OK -- but we will check.
> >
> > Thanks again,
> > Jim