Re: K-T Theories

["Mike Styzen Shelf Expl, 588-4308" <mstyzen@shell.com>]

If you are going to cause K/T extinctions with diseases you don't need
to give the disease to big terrestrial vertibrates at all.  If you want
to kill lots of things what you have to attack is the phytoplankton (I
know some of you are going to think "Here goes that nannofossil guy
again"). Really though, most of the earth's photosynthetic biomass is
unicellular algae.  I dont think most people know exactly how abundant
this stuff is.  I don't ever see barren samples, even from sediments
deposited in the most turbid of conditions.  If you suddenly wipe out
the phytoplankton (lots of evidence for this at the K/T) you upset the
worldwide carbon cycle, the oxygen cycle the silicon cycle and probably
other vital things I haven't thought of.  Plankton also has a connected
population, there is really only one ocean, so there is no reason to
jack land bridges up and down to connect populations.  In the
Cretaceous there was even more continuous circulation in the low
latitudes than there is today.  Ok that's probably enough frothing at
the mouth from the nanno guy...But remember dinosaurs are just the
glamour critters of the big die off at the K/T if you are going to
consider causes you have to look at the whole ecosystem.
Mike
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|      Michael J. Styzen               Phone: (504) 588-4308            | 
|      Shell Offshore Inc.             Room:  OSS-2920            
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|      P.O. Box 61933                  Email: mstyzen@shell.com         | 
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