Re: Pterosaur structure, good job JC

[jrc <jrccea@bellsouth.net>]

Comments inserted.
JimC

----- Original Message ----- 
From: "John Conway" <john.a.conway@gmail.com>
To: "David Peters" <davidrpeters@earthlink.net>
Cc: "dinosaur mailing list" <dinosaur@usc.edu>
Sent: Friday, January 11, 2008 10:53 AM
Subject: Re: Pterosaur structure, good job JC


> > When the wing fingers are placed into the standard tetrapod configuration 
> > .......How can this happen in this configuration without some sort of 
> > strange humeral configuration?

To place your own arms in the position John illustrates, just stick your 
arms out to the side, bend them upward at the elbows so that the palms face 
one another over your head.  Now straighten your elbows so the palms face 
upward.  Then lie down on your stomach with out moving them relative to your 
body (if you can do that without going kersplat, I wanna watch !! ).  This 
puts your torso and body in pterosaur cruise flight position, just as John 
illustrates.  No strange humeral configuration required.

> I don't see your problem to be honest. All you need do is swing the arms 
> down and bam! walking position, with the fingers aligned with tracks.

Correct.  It also aligns the limbs appropriately for launch out of the 
terrestrial positioning.

> Ah, well, I think Chris provided a decent scenario for how that might have 
> happened at Flugsaurier.

Chris has been describing that for a long time now.  The guy is talented and 
gifted with remarkable powers of observation..

> I actually prefer the hip-attachment for pterosaurs like this myself, but 
> variety is the spice of life and all that.

I was trying to say that, but you done it better  :-)
I suspect that when the fossil record fills out a bit more, we'll see 
pterosaurs with multiple attachment modes all the way from hip attachments 
to full broadwing ankle attachments.  Like John, I prefer the hip attachment 
for Anhanguera and Quetzalcoatlus -- but, there is no fossil evidence to 
support that and other evidence that purports to support ankle attachments 
is still somewhat ambiguous.  The door is still open for multiple attachment 
scenarios (my personal preference).  Spice, life, and all......

> I was originally going to to draw this with several different attachment 
> versions, but I decided I'd spent too much time on it already, and went 
> with a 'compromise' position.