Snorkeling Sauropods, Batman! (Was: DINOSAUR digest 3445)

[Mike Taylor <mike@miketaylor.org.uk>]

> Date: Wed, 11 Jan 2006 06:05:12 -0800 (PST)
> From: Jorge Dichenberg <jorgedich@yahoo.com>
> 
> I think most sauropods were terrestial. But
> theoretically some could be semi-aquatic like hippos.
> They would swim and dive, feed underwater and
> resurface to breathe holding neck horizontaly and back
> above water. Nothing in physics prevents it. 

... except the low density of sauropods.  Again the Wedel 2005 paper
demonstrates that 10% of the volume of _Diplodocus_ is taken up by
intravertebral air-spaces -- that's before you even consider the long
trachea, lunch, pulmonary air-sacs and soft-tissue diverticula.  These
were very spongy animals!  :-)

> That old scientist overlooked one thing. All living
> animals have density around that of water.

There are plenty of extant birds with density well below that of
water.

> Even if typical sauropod was a little heavier than
> water, evolving buyoance was easy. Fat and air sacs
> are lighter than water. Average sauropod could
> actually be lighter than water and have trouble with
> diving, not with breathing on the surface.  

Precisely.

 _/|_    ___________________________________________________________________
/o ) \/  Mike Taylor  <mike@miketaylor.org.uk>  http://www.miketaylor.org.uk
)_v__/\  "When I can't fondle the hand I'm fond of, I fondle the hand at
         hand" -- E. Y. Harburg, "Finian's Rainbow"