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Re: EXTINCTION & Breakup



> then you would expect the breakup to ...
>  provide a stimulus for an increase in diversity rather
> than a decrease.

I believe that an increase in diversity is what is seen through the
late Jurassic and early to mid Cretaceous, so this supports your
expectation.  The later Cretaceous shows a decrease in diversity, at
least of dinosaur species, possibly because of the raising and drying
out of inland seas; this would tend to mix geographically separated
populations and decrease diversity through predation, disease, or other
specific extinction mechanisms.  I note that some genera, such as the
ceratopsians, seem to show an almost wild diversification at that time,
but the number of genera decreases.

How far off am I, you folks who really know?  :-)

-dick

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