Re: DINOSAUR digest 3384

[don ohmes <d_ohmes@yahoo.com>]

I did not say they used the neck as a snorkle. 

WARNING: ENTIRELY SPECULATIVE FROM A _BEHAVIORAL_
PERSPECTIVE-- 

I am saying their mass allowed them to store a lot of
o2, and therefore they might have been able to hold
their breath for a significant period of time (> 30
minutes) w/ minimal diving adaptations (slow
heartbeat/metabolism). No need for (deep) snorkling.
Note also that in water 3-4m deep the lungs would not
have been far below the waterline. (Limit was ~1.3 m
depth for me, breathing through a length of garden
hose, circa 1965).

With lungs less than full, they probably could achieve
negative bouyancy and walk on the bottom of the
"pool", like hippos, and me (20-30 seconds). [DON'T
TRY THAT AT HOME KIDS, IT IS VERY DANGEROUS...]

It is plausible that they were _physically_ capable of
such activities when accessing whatever resources were
available in the shallow aquatic environment.

Which reminds me--
When I was 10-11 years old, I took part in an old
Southern tradition called "muddying-up". It involves
stirring up so much silt in a small pond that the fish
float to the surface, knocked out by o2 deprivation;
then you scoop them up in a #2 washtub and take them
home...

If sauros did ever enter small ponds, they probably
stirred up a lot of silt. Ooops, that is right, they
might have bogged down. Maybe they're necks were real
long so they could drink w/out getting too close to
the water's edge... LOL.

Don

--- K and T Dykes <ktdykes@arcor.de> wrote:

> <<I am _not_ trying to say this is germane to k/t
> extinction patterns (don't
> think it is); nevertheless, I would like to point
> out that the ability to
> hold breath correlates positively w/ body size.
> Large dinos may not have
> needed (detectable) adaptations to stay submerged
> for significant periods of
> time. Never seen this mentioned in discussions of
> sauropod lifestyles...>>
> 
> I can't claim to be a follower of sauropods, Don,
> but the large ones would
> presumably have required extraordinary lungs to
> withstand the water
> pressure.  I'm reminded of an Austrian researcher
> I've forgotten the name
> of.  He apparently twice tried breathing through
> long snorkels in a swimming
> pool, in order to demonstrate the difficulties.  The
> second and longer
> snorkel proved more difficult than expected, as it
> resulted in a fatal heart
> attack.  His research got no further.
> 
> I think Michael Benton is the source for that,
> (possibly in The Book of
> Life).  It's quite possible I've mangled some
> details.
> 
>