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RE: Rethinking What Caused the Last Mass Extinction
The article mentions the top of the bed is missing so the Strangelove
deposit must be an unconformity. Does not say what the Pinna bed is but
they do describe it as rock and soil! I cant think how ammonites would get
into soil without being re-worked.
From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
Sent: 06 November 2007 12:22
Subject: Re: Rethinking What Caused the Last Mass Extinction
Interesting. Is reworking ruled out? (Not from the condition of the
specimens in the photo.)
Because... I don't see how it's possible to have a local extinction of
ammonites. Ammonites had planktonic larvae. Either you kill them all
worldwide at once, or the survivors fill the oceans again within a few
generations, as happened after the Devonian-Carboniferous, the
Permian-Triassic, and the Triassic-Jurassic mass extinctions. In other
words, the fact that the ammonites are extinct is good evidence that they
died out in a catastrophic mass extinction.
This is consistent with the last paragraph of the article, which describes a
Strangelove ocean above the supposed Paleocene ammonites.
Bringing up supposed gradual dinosaur extinctions doesn't earn the article
any brownie points... (And "rethinking" is an extremely unfortunate word