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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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