Re: FOUR, THREE, TWO, ONE . . . PTEROSAURS HAVE LIFT OFF!

[Michael Habib <mhabib5@jhmi.edu>]

It's a bit of a strange paradox, actually: while most workers have 
preferred a quad stance for walking, every previous paper that has ever 
mentioned launch dynamics in pterosaurs has assumed a bipedal launch.  
That is, the general assumption was (for reasons I don't really 
understand) that the animals switched to biped running to take off.  
Bramwell made this assumption, as did Chatterjee, etc.  The only 
explicit quad-launch models have been Jim's presentations (until my 
presentation in Munich and the current paper).

While you and I have disagreed about pterosaur stance, I definitely 
give you credit for being consistent (i.e. both walking and launching 
using the same gait).  *Switching* to a less powerful gait to takeoff, 
by contrast, is rather odd.

Here is the full reference:

Habib M.  2008. Comparative evidence for quadrupedal launch in 
pterosaurs. Pp 161-168 in Buffetaut E, and DWE Hone, eds.  Wellnhofer 
Pterosaur Meeting: Zitteliana B28

Cheers,

--Mike

Michael Habib, M.S.
PhD. Candidate
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205
(443) 280 0181
habib@jhmi.edu

On Thursday, January 8, 2009, at 09:14  AM, David Peters wrote:

> I'll look forward to reading the paper, but one thing stuck out in the 
> description:
>
> "Assumption and convention — rather than reason or data — held sway 
> for centuries, ever since the classical bipedal model of pterosaur 
> take-off was first championed, he notes."
>
> Who, besides Padian (1983a, b)  and myself, have championed the 
> bipedal model? I thought everyone else considered quad the way to go.
>
> David Peters
> davidpeters@att.net