Re: Selective Extinction

[Chris Campbell <sankarah@ou.edu>]

Peter Von Sholly wrote:
> 
> An old and often asked question about the final dinosaur 
> extinction is why certain animals went and others didn't.  I read 
> somewhere recently about an impact theory wherein a wave of hot 
> gasses swept across the land destroying most everything in its 
> path.  I wonder if there could be anything in the idea that 
> creatures who lay low to the ground (crocodiles, lizards, turtles, 
> snakes, frogs, small mammals, many insects etc) would have been
> spared in such a scenario (even some birds and flyers high up in 
> the air might have been missed by the main devastation).  But 
> bigger animals that stood with higher profiles made better targets 
> and were simply mowed down.  This is obviously not the whole 
> picture but it does seem that the animals who survived were closer 
> to the ground that those who did not.

And this would explain the extinctions of sharks and mososaurs how,
exactly?  The impact theory explains nothing except geological
evidence.  It cannot account, in any of its forms, for the extinctions
of any animals whatsoever.  Whether or not an impact occurred is no
longer an issue; it certainly did.  It did not, however, do much of
anything significant that wasn't already being done on a variety of
other fronts; it was just a bad day in a series of crummy years.  The
collision of India with Asia, the regression of inland seas, the
invasions of new species, and gradual climactic changes were all taking
their toll long before our ol' KT asteroid hit.  

Chris