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Re: Theories on the extinction of dinosaurs



In a message dated 11/14/99 8:08:25 AM EST, jbois@umd5.umd.edu writes:

<< On Sat, 13 Nov 1999 Dinogeorge@aol.com wrote:
 Bois said:
 >>  Extrapolating from that to a world-wide instantaneous
 >>  extinction is un-scientific. 
 > 
 >  Fair enough. Meanwhile, please indicate anywhere in the world where 
 > dinosaurs are known to have survived into the Paleocene.
 
 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.  >>

>All< current evidence indicates that non-avian dinosaurs became extinct at 
the K-T boundary, not at different times in different places. There is still 
some leeway around the boundary because of dating error margins and things 
like that. This is a relatively short time span, which is why it is difficult 
to find localities where exactly this time span occurs in the geology. As a 
counterprediction, let me predict that wherever the K-T boundary occurs at a 
locality, any dinosaurs at that locality will appear below it and no 
dinosaurs will appear above it. (This is what is found in the Deccan deposits 
in India, by the way, which straddle the K-T boundary. According to 
Chatterjee, dinosaur fossils occur plentifully in the lower parts, then there 
is the K-T boundary clay, above which there are no more dinosaurs. This is 
described in his paper on the Shiva crater, another K-T boundary asteroid 
impact.)