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Re: sauropod lung collapse



> Date: Tue, 10 Jan 2006 15:02:55 -0500
> From: "W. F. Zimmerman, wfzimmerman.com" <wfz@wfzimmerman.com>
> 
> This doesn't clinch the case, does it?  Plenty of large animals like
> hippopotamuses and, yes, whales manage to spend quite a bit of time
> deep under water without having collapsed lungs and do their
> breathing when they're safely above water.

Yes indeed.  No-one (to my knowledge) has ever claimed that sauropods
couldn't survive with their lungs submerged, only that they couldn't
inhale.  And this claim is true.  Why?  Because what inflates your
lungs when you inhale is atmospheric pressure; and as soon as your
lungs are far enough below the water level that the water pressure
exceeds atmospheric pressure, the net pressure is zero and it's
impossible to inhale.  If I were more rigorous I'd now go on to
calculate the depth at which water pressure reaches one atmosphere,
but I'm sure someone on the list will already know this.

(Of course all this is academic, as sauropods were so extensively
pneumatised that there were probably the least dense non-avain
vertebrates of all time, and would certainly have floated had they
attempted to walk on the bottom of a lake.)

 _/|_    ___________________________________________________________________
/o ) \/  Mike Taylor  <mike@miketaylor.org.uk>  http://www.miketaylor.org.uk
)_v__/\  "Anyone can see that Michael Owen represents Carlsberg and Reebok.
         But you'd need binoculars to notice that he also plays for
         Liverpool" -- George Monbiot, writing in the _Guardian_