🚀 go-pugleaf

MH Roberts wrote:
> 
> Neil O'Hara wrote:
> > The object that struck earth and killed the dinosaurs was more likely a
> > comet, but could have been a meteor,...
> 
> I studied geology last year at college, and an I didn't realise until
> then that most geologists refutre the claim that a projectile from outer
> space killed off the dinosaurs.  This is mainly because Palaeontological
> evidence suggests that the dinosaurs were extinct by and large before
> the event occurred.. and the theory was proposed by a physicist who had
> little knowledge of geology..

Is it possible that your geology textbooks are 10 - 15 years old?  What
about the enriched iridium layer just above the K-T boundary?  What
about the crater evidence off the Yacatan that has been identified as a
possible 'smoking gun'?

Stephen Jay Gould addressed the issue of dinosaur fade-out awhile back
in his column in Natural History. If only a few fossils of any
particular species have been found, just because the most recent find is
a few million years before the KT boundary, doesn't mean the species
died out at the time of the last known fossil.  Gould reported on an
intensive seach just below the boundary for a species believed to have
faded out before then.  It was found, demonstrating that that particular
species was in fact present to the 'end', and suggesting that more
careful searching would probably document many others. Regardless, there
are unquestionably many species of dinosaurs (and other creatures) which
are present in the fossil record prior to the KT boundary, and
completely absent afterward.

I admit that its been a few years since I took college geology - - the
Alvarez's were still considered a laughingstock for suggesting such a
silly idea as a dinosaur-killing comet when I was in college.  I relate
my understanding of the subject based on 'popular science' readings, but
I think it's a fairly good interpretation ofthe 'known facts'.

Neil