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Re: Theories on the extinction of dinosaurs



At 10:20 AM 11/12/99 -0500, Seosamh wrote:
>
>Since all three (impact, volcanism, increased atmospheric oxygen) are
accepted 
>as real events occurring near the end of the Cretaceous, and the world wide 
>mass extinctions took place then, is there some obvious gap in how those
three 
>items might tie together? 

In what sense?  In the sense that they all occurred and caused possibly
synergistic biological effects?  Or in the sense of them having a common cause?

The latter is almost entirely out of the question.  And it is unnecessary
as well.  Synergistic effects between various *independent* events is a
perfectly valid mode of explanation.

[Note, I am not yet convinced of the reality of the change in oxygen
levels, but you also left out a few other events: worldwide drop in
relative sea level, and possible widespread oceanic anoxia, to name just two].

>I used the metaphor of a jigsaw puzzle. We have several pieces in the fossil 
>record. We have a notion of the broad outline of the puzzle, i.e, a plausible 
>description of the extinction event(s) with causes and effects. What kind of 
>information would enable us to say, "Of course!" and clear up the mystery?

A time machine?  A time scope?

--------------
May the peace of God be with you.         sarima@ix.netcom.com