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RE: Why non-avian dinosaurs weren't able to survive
On Mon, Nov 23rd, 2015 at 11:29 PM, "Thomas R. Holtz, Jr." <tholtz@umd.edu>
wrote:
> Many different possible answers, but at present we can't tease out which
> one(s) is/are correct
> [SNIP]
> So there are many possible reasons.
And never discount pure dumb luck. We can hypothesise all we like about
possible mechanisms for
extinction, but sometimes all it takes is a bit of bad luck to tip a species
over the edge of extinction
(or conversely, a bit of good luck to preserve a closely-related and
ecologically-similar species).
I expect extinction is never clearly 'this' or 'that', but rather 'a bit of
this' in combination with 'a bit
of that' with a dash of 'something else' thrown into the mix. Life doesn't
survive a billion years of
continuous descent without having a suite of survival mechanisms at its
disposal. It would take a
combination of several detrimental factors all happening to coincide to wipe
out an entire genus, let
alone whole families. Even then, I doubt there is any single blanket
combination of factors that can
explain all extinctions during a major extinction event. Each genus (possibly
each species)
probably had a slightly different combination of factors leading to their
demise.
--
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Dann Pigdon
Spatial Data Analyst Australian Dinosaurs
Melbourne, Australia http://home.alphalink.com.au/~dannj
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