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Re: Mammals as a cause of Dinosaur extinction



On 17 Dec 1997 06:36:35 -0500, Richard Keatinge
<richard@keatinge.demon.co.uk> wrote:

>In article <675mb9$g8l@mtinsc03.worldnet.att.net>, Stan Engel
><thorisporn@worldnet.att.net> writes
>>I do not claim that mammals were the sole or even a major cause of Dinosaur
>>extinction. I believe that it was a factor and should not be summarily
>>dismissed.
>>
>
>This is possible, but rather difficult to test.  Mammals quite fail to
>explain the large-scale *marine* extinctions at the K-T - even whales
>didn't evolve until later.  Or the fact that dinosaurs, and pterosaurs,
>became extinct on every land-mass at (very roughly) the same time.  And,
>of course, mammals had been around for tens of millions of years by
>then.  The most parsimonious hypothesis is that non-avian dinosaurs
>would still be extinct even without mammals around. 
>
>OTOH it's easy to imagine that having nasty sharp-toothed little
>nocturnal scavengers around wouldn't exactly help any self-respecting
>egg-layer.  Dodos are the obvious example.  Just maybe, we'd have
>ceratopsian descendants instead of rhinoceroses, if some mammal hadn't
>eaten the crucial egg.  A nice idea, serving our cladistic,
>homeothermic, hairy, nipple-oriented pride, not indeed to be summarily
>dismissed.  But, for the foreseeable future, it is in the realm of idle
>speculation.  
>
>
>-- 
>Richard Keatinge 
>
>homepage http://www.keatinge.demon.co.uk