Re: John Bois on Armadillos at the K/T!

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

Fabio Marco Dalla Vecchia wrote:

> Dear Jim,
> I think that the giantism is a "background" phenomenon in pterosaur history.
> The fact that "giant" pterosaurs are very large [giantism is relative: a
> "rhamphorhynchoid" pterosaur with a 2.5 m wing span was a giant, but who
> cares about it?]

Me.  But then I care about the teeny ones too.  Extremes in both directions
interest me.

> ...., later being
> supplanted by Azhdarchid giantism just because Azhdarchids supplanted
> Ornithocheirids and Pteranodontids during latest Cretaceous times.

Good point.

> Thus the
> question is: why Azhdarchids supplanted Ornithocheirids and Pteranodontids?

This is a better question than the one I asked.  I don't know the answer to it,
either.

> The answer is probably unrelated to size but possibly lies in the different
> wing structure, in something related to the ecological pressure or simply
> in historical contingencies difficult to identify.

The relatively shorter outer wing appears to be tightly related to the
development of the relatively long, inflexible neck.  The inflexible part 
appears
to be for aerodynamic reasons, to help compensate for having a center of 
pressure
so far in front of the center of lift.  My previous speculation implied
ecological pressure (or rather opportunity).  As you say, historical
contingencies may be the cause.  If so, I hope they are eventually identified.

> P.s. - What about Wann?

The QE2 was diverted from New York to Boston, and Cunard offered to bus them 
home
from there.  I think our two bus trips from Toulouse may have affected their
decision to rent a car instead.  It took them 2 1/2 days to drive home from
Boston, but they made it in good shape.  Wann's stamina never ceases to amaze 
me.

How about you?  Lela and I met and made a lot of new friends during the
symposium, and we've been sort of worried about all of you during the last few
weeks.  All is well here.

All the best,

Jim