Re: Biomechanics

["tons" <tons@logicsouth.com>]

Matthew Bonnan <mbonnan@hotmail.com> said:

Ooo ... careful, careful.  It's not so much the CO2 as the air pressure
> differential that gets we humans.  When you're breathing atmospheric
> pressure oxygen but having your lungs squeezed by several atmospheres of
> pressure, that's where the real problem lies.  A better test of your CO2
> idea would be breathing through a long tube in the SAME atmospheric
> pressure.

Well they both can get you but dinosaurs would have no way to breathe
pressurized gases.  I was using the analogy of dead space which if increased
causes increased CO2 partial pressures in the lungs and hence equalizing to
the body.  Sauropods have long necks and therefore (probably) a lot of dead
space.  I haven't had the time to look at giraffe physiology but would love
a quick freebie from someone.

> Water is very heavy stuff (approx. 8lbs. per gallon!) and every 10 ft or
so
> below the surface adds another atmosphere of pressure -- hence the
> pressurized tanks of divers and the bends.  If we momentarily disregard
> pneumatization of sauropod vertebrae (not limb bones which were almost
> completely solid), if you have a nose sucking in air at atmospheric
pressure
> but lungs which are, let's say 30 feet below the surface, you may have
some
> problems on your hands.
>
You may be correct as I was making an educated guess.  But you would not
have to lift the water but only displace it to breathe.  Don't get breathing
essentially atmospheric pressurized gases confused with water pressures.  I
personally believe it is physiology possible for a large sauropod
to"snorkel" but I doubt they could or would.  First the animal would
probably swim with its head well out of the water (another guess).  Even if
it wanted to "snorkel" it would have to walk in water at exactly the right
depth to allow it or somehow swim "underwater" with only its head out of the
water.  Perhaps this is possible.

Best

Michael Teuton