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Re: Theories on the extinction of dinosaurs



----- Original Message -----
From: dbensen <dbensen@gotnet.net>
To: <jbois@umd5.umd.edu>
Cc: <Dinogeorge@aol.com>; <kirkam@wam.umd.edu>; <dinosaur@usc.edu>
Sent: Sunday, November 14, 1999 1:28 PM
Subject: Re: Theories on the extinction of dinosaurs


> >>I predict it.  I am still in the hypothesis-forming stage.  You have
moved
> on to a position which, given current evidence, is untenable.  Simply, the
> null hypothesis: Dinosaurs became extinct at different times in different
> places, is not falsifiable using a single data point. <<
>
> That woulnd't work.  For instance, if all the dinosaurs in Asia were
driven
> extinct by a meteor, then after the dust had cleared, the dinosaurs from
other
> places would recolonize the continent. And remember pterosaurs, which can
fly
> away from localized disasters.  Something would have to kill off _all_
> dinosaurs _everywhere_ for any mass extinction to take place.  Perhaps
minor
> disatsers at various times through the K killed a few million dinosaurs
here
> and there, but there would have to be some _big_ disaster at the end that
> finished them all off.
>
> Dan
>

I can see the logic here, but how much time are we talking when we're saying
"all at once"?  Is there any way to study how long it took the dinosaurs to
disappear after the impact at a site that spans the K-T like Hell Creek?  Or
are the measurements needed for such a calculation just too precise to
determine with K-Ar dating (or whatever else they're using =) ?

Andrea Kirk
Undergraduate, Computer Science
University of Maryland