Re: Mamenchisaurus Posture Paper

[David Marjanovic <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Roger Seymour" <roger.seymour@adelaide.edu.au>
Sent: Thursday, June 02, 2005 1:49 AM

> A sauropod in water would not be affected by gravity on its circulatory
> system.  It could hold its head vertically in either direction and it
> would have almost no effect on the pressure at the heart.  Its neck
> could be as long as you like.

I disagree for a completely different reason -- the neck vertebrae of 
derived sauropods contain more air than bone, and this doesn't count the 
windpipe and eventual air sacs in the soft parts of the neck; getting the 
entire neck under water would probably have required considerable muscular 
effort.

> This is why I like floating sauropods with their lungs on the surface.

Rather "above" than "on".
http://dml.cmnh.org/2003Dec/msg00125.html
http://dml.cmnh.org/2003Oct/msg00324.html

Probably access to this report is now free:
http://www.sciencemag.org/cgi/content/full/302/5645/549a

> The problem for this idea comes from the Morrison Formation, which is
> usually described as upland, floodplain overbank.  Where is their deep
> water?

Apparently nowhere...