Why the ammonites?

["dinotracker" <dinotracker@earthlink.net>]

    John Bois asked, "Why were ammonites targeted by the bolide in your
view?"

    O.K., John didn't ask that of me, but I can't resist contributing my two
bits worth in on this:

    Well, since cosmic bodies (whether asteroids or comets) are not very
intelligent, I doubt it targeted anything. :)

    Also, whys are the province of philosophers.   Hows are the province of
science.  So let's reword the question and add something to it.  Then, the
answer is quite thought provoking:

    How is it that ammonites became extinct as a result of the K/T impact,
when nautiloids did not?

    According to the author of the fascinating book, THE GREAT DYING, whose
name I cannot recall off hand, the egg casings of ammonites were primarily
calcium carbonate, while the egg casings of nautiloids were primarily
magnesium carbonate.  Thus, as a result of acid rain, the oceans became
sufficiently acid as to dissolve egg casings of calcium carbonate (those of
ammonites), while egg casings comprised of magnesium carbonate (those of
nautiloids) endured sufficiently to allow the nautiloids to reproduce right
on through the periods of unusually acid oceans.

    If anyone wants more data on the book and its author, ask, and I will
obtain it tomorrow, at the library.

    Ray Stanford

"You know my method.  It is founded upon the observance of trifles." --
Sherlock Holmes in The Boscombe Valley Mystery