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Re: Dodos, Swifts and Quetzalcoatlus.



Graydon wrote:
> 
> > or walking bipedally.  Perhaps demonstrating the same lack of need.
> 
> That's a nearly vertical posture?

Nineteen feet to the eyes would be.  Eighteen feet to the eyes in a
quadrupedal posture assumes the spine is oriented about 30 degrees off
the horizontal (the length from acetabulum to notarium socket is
estimated to be about 30 inches, or 2.5 feet). So the difference in
height between quadrupedal and vertical bipedal is about 2.5-2.5*sin30,
or 2.5-1.25 = 1.25 feet. Not much difference.
> 
> (I don't suppose there are some stick figure drawings available
> somewhere?)

No, but one could be whipped out pretty quickly.  John?  Or, I have a
schematic scale drawing of a Quetz standing beside a giraffe that I did
in AutoCad.  Can you read an AutoCad *.dwg file?
> 
> Oh, and is 18 feet from a particular specimen, an expected average, or
> an upper limit?

With only one specimen of Qn to work from no one can be sure, and the
assumption would be that it would be about average.  The 18 feet is with
the neck placed pretty much vertical to get the eyes about as high as
possible for peeking about and checking the surrounds (and to compare
with the bipedal position).  In normal posture, the eyes might be more
like 16 feet or so off the ground.

> Somehow, the idea of something that flies so tall that a tyrannosaur
> couldn't look it in the eye is making the sheer size of the things
> emotionally real in a way which wasn't previously the case....

There are at least 3-4 azhdarchid species (one possibly unpublished)
that approach this size.  Personally, I think slightly larger ones may
well be found.  As an interesting aside, should a predator charge one of
these beasts from any direction other than the front quarter, then by
the time the pterosaur's hands leave the ground, it is already traveling
faster than any likely predator would be able to run.  The beasties were
durned near uncatchable.
Jim