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Re: dino extinction



From: Jeffrey Martz <martz@holly.ColoState.EDU>
 >      Out of curiosity, what is the current state of the gradual vs.
 > rapid extinction of dinosaurs?

Very uncertain.

There is little evidence of obvious declines in diversity at the
family level across the Late Maastrichtian (using three subdivisions).

On the other hand, the resolution of the terrestrial fossil record,
especially of large vertebrates, is very poor, and so a gradual decline
in, say, the last quarter of the Late Maastrichtian might well be
indetectable anyhow.

Then again, the *generic* diversity of the best known Late Maastrichtian
dinosaur faunas is well below that of the comparable Early Maastrichtian
fanuas.

But, there is, as yet, no good statistical evidence for a reduction
in generic diversity *during* the Late Maastrichtian.


In short: the issue is far from decided.

 >       I am of the (largely unfounded) opinion that mass extinctions are
 > all related to a lot of factors occurring coicidentally.

I agree, but I like to think I have some strong circumstantial evidence
for this position, at the very least.

swf@elsegundoca.ncr.com         sarima@ix.netcom.com

The peace of God be with you.