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Re: More Quetz Questions

I can't resist..... WFTP
Other comments inserted below
If you wish, feel free to contact me offlist about the 1/10 sculpture at jrccea at bellsouth.net

----- Original Message ----- From: "<Bruce Woollatt>" <brucewoollatt@hotmail.com>
To: "dinosaur" <dinosaur@usc.edu>
Sent: Thursday, January 17, 2008 10:14 AM
Subject: More Quetz Questions

I'm in the process of sculpting a
1/10 model of Qn for my local library branch and I want it to be as
accurate (and as convincingly
lifelike) as possible. I know that its remains are fragmentary and
that at some point I'll just have to take a chance and start building
something that may turn out to be wrong.

The Q species remains are pretty complete, and there is a fair to middlin' idea of how they might scale up to a Qn sized critter. Personally, I find Q species far more interesting than Qn.

I hope to put in progress
shots up on my flickr page http://www.flickr.com/photos/12388840@N06/
as I work on the not so wee beastie. So here goes;

In Wellnhoffer's Illustrated Encyclopedia of Pterosaurs, there is a photo
purporting to be a Quetz pectoral girdle. Is this identification
indeed correct?

From memory (I don't have Wellhofer in front of me, and am too lazy to go in
the other room and dig it out of whatever pile it may be buried in), the photo is of the Qsp pectoral girdle. The Qn pectoral girdle is not preserved. There would be substantial allometric differences between the two.

I still see lots of Q restorations in which the
anterior of the dentary and premax are fashioned after those parts
labeled as being from Q in the same book. (They're now thought to be
from a Tapajeroid are they not?)

They were thought to be from a tapejaroid at the time. That was a typo. The pictured specimen was from further down in the Big Bend Morrison, and the typo has hung around to haunt us.

I'm wondering because the supposed Q
pectoral girdle seems to have been photographed on the same blue scale
grid as the jaw tips.

It was. As an aside, that was a 6 inch square scale grid.

In the photo of Dr. Langston studying the range of motion of Qsp. in
the same book, which way is the wing articulated, right way up or
inverted? It's hard for me to tell.

Well, crap. I will have to go find the book. Will holler back at you. It's easier to support the thing upside down, so it may well be. I don't remember without looking at the photo.

Am I correct in my understanding that Qn's wingspan is now thought to
be less than originally estimated and that this reduction is from a
re-estimation of the length of distal wing elements?

No. Wann estimated it at about 36 feet pretty early on, that that remains the number in use today. Depending on what the animal was doing in flight, it would often be transiently less than that. I've seen span numbers up to 50 feet, but they are bogus.

For some reason
the figure of 36 feet comes to mind rather than the earlier estimates
of 39 feet.

36 feet is close enough for government work :-)

The recently posted shoulder to acetabula length estimate of 64cm for
Qn seems to be a lot shorter than DR. Langston's restoration

If I remember correctly, 64 cm is about the length used in Matt Smith's Qn skeletal sculpture that hangs in the TMM at Austin. Wann and I were advisors on that sculpture (Wann was the principal advisor). And, it wasn't exactly the shoulder -- it was the notarium rather than the glenoid.

(I think
in an article in Science from 1981 if I've got it right. I'm thinking
of the drawing comparing Qn with a little naked spread-eagle dude
standing beside, with Q's body a  very schematic inverted tear-drop
shape and the neck and head incomplete.)  Is this restoration still of
any use ?


I've seen so many variations on proportions I'm not sure
which to use.

Except for a good fraction of the left wing, Qn is not preserved. All other dimensions are allometric morphs of Qsp. You might try the proportions of the TMM sculpture, though that skull is too gracile and probably about a foot too short, and that scapulocoracoid does not resemble what the real thing would have to look like.

There are slight differences in everything I've looked at.

Don't worry, you will continue to see a lot of differences till more fossil remains are found.

The main ones I've been looking at are by Langston, Sibbick (a
pencil study I saw online, apparently for his National Geographic

John's work is beautiful, but his Wellhnofer illustrations have the wrong mandible, the leading edge and top of the crest don't match the preserved Qsp crest, and the proportions are somewhat outdated. The National Geographic illustrations are of Qsp, and those proportions were somewhat modified to fit them on the National Geographic page layout. Wann and I were among the technical advisors for that layout. I think Dave Unwin and maybe Dave Martill were too, but have forgotten (sorry, Dave, I'm having a senior moment :-) When looking at the National Geographic illustrations, keep in mind that there is no tendon running from the tip of the pteroid in toward the shoulder.

Paul's size comparisons from Dinosaurs of the Air, and
Mark Witton's drawings, among others. Which (if any) published
restoration do you find most accurate, (or at least likely)
particularly regarding basic proportions?

Photographs of the TMM skeletal sculpture. There is a photo of that sculpture or a copy in the National Geographic article from about 2001 or thereabouts -- somewhere roughly around page 100-104, if I remember correctly.

That's all (again, for the moment). This discussion has been very
interesting, informative and entertaining, not to mention helpful.

Thanks again,