acid Sig-Lipps

[jlipps@xxxxxxxxxxxxxxxxxx (Jere H. Lipps)]

Check out D'Hondt et al in Geology  22:983-986 (Nov. 1994) for a good
analysis of acid rain.  Unlikely it did it.

Signor-Lipps could certainly account for the last meter of missing verts.
The record in all environments is generally poor enough that
paleontologists should not rely on such details.  Two factors enter:
sampling error=we just missed finding the stuff; and bias=the animals
simply did not live at a site throughout the entire time of their
existance.  In other words they emmigrated or migrated out of the site of
deposition.  True, not only for verts, but for the microplankton too.
That's largely why they show a Sig-Lipps.  Dave Lindberg and I have a paper
in the works doing a complete reanalysis of Sig-Lipps and it cannot be
avoided.

What paleontologists can do best at these extinction events is to say
something about conditions before and after, not during, the event, and how
the faunas/floras changed systematically.   There was certainly an
extinction of dinosaurs (even if some are hiding out in the jungles today)
based simply on what we've known for years about the generalities of their
distribution.  If we develop models for the changes we see and ask that the
non-paleo types reconcile those bio-based models with their own, we might
see some progress on this.  As long as geophysicists keep telling us how
dinosaurs +others went out and we keep telling them our stories, we'll
never get at this problem.  The K/T extinction event evidence comes not
from paleo so much, but from geochem, mineralogy, and geology.  At least in
detail.

Jere


Jere H. Lipps
Professor, Department of Integrative Biology
Director, Museum of Paleontology
University of California at Berkeley
Berkeley, CA 94720
510-642-9006 fax 642-1822
jlipps@ucmp1.berkeley.edu