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Re: Dinosaur ecology: hermetically sealed?



--- John Bois <jbois@umd5.umd.edu> wrote:

> The story goes: a bolide hits; Earth's atmosphere
> holds particulate matter
> and retards photosynthesis.  This goes on until all
> herbivorous dinosaurs
> die off.  Having no food, carnivorous dinosaurs also
> become extinct.
> But surely there were dinosaurs that ate mammals,
> lizards, crocs,
> snakes--species whose diversity was little affected.
>  While I realize we
> have no population data, no estimate of food needed
> or available, the
> likely availability of _some_ food, especially for
> the smallest
> meat-eaters, poses a challenge: why didn't some
> survive?

>From what I recall, even the most enthusiastic "meteor
people" admit that a calamity like such an impact
would have pushed already-stressed populations over
the brink rather than being the sole cause of their
extinction.

Who was it that wrote that non-avian dinosaurs were
ultimately victims of their own success, that, in the
late Cretaceous, the remaining species were so
specialized that they crowded out more "generalized"
forms, and then the sudden dramatic changes from the
impact made it difficult for the "specialists" to
adapt to the destruction of their niches, adaptations
the more generalized species could possibly have
achieved?  (Was it Horner?)  At first it sounded fine
but upon further reflection it leaves me scratching my
head.

If I may, let me turn your question around, giving you
an opportunity to elaborate in the process.  If I
recall correctly, you posit that someone ate all of
the dinosaurs' eggs.  How do you account for the
extinction of many other species, particularly the
marine reptiles?

=====
Larry

"I've been ionized, but I'm OK now."

http://members.tripod.com/~megalania/index.html

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