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Re: Ocean EcoSystems Unexpectedly Stable (fwd)

Bois said: 
> > I wonder what it was that departed as a result of the event that so
> > "emptied the world"?  After all, rudists were gone before,
David M. said:
> Is that "still true"?

Bois, emphatically replies:

I think.

> > ammonites had suffered a Cretaceous-long decline.

> A decline throughout the K? Which strange sort of competition or whatever
> could cause that? I mean, the K was longer than the time that has passed
> since! -- In some places ammonites do appear to die out gradually, but in
> others in the vicinity they last to the very end.


This link copies the figure from Officer and Page's The Great Dinosaur
Extinction Controversy.  Data is from Wiedmann 1969 (ref. if needed) and is
unchallenged as far as I know.  If the record represents reality ammonites
were more successful early in K.
Also, in same link, notice inoceramid clam extinction earlier than K/T.  Saw
a paper in recent (Lethiae sp?) journal talking about predation as cause for
their extinction.

>     From the distribution of Maastrichtian elasmosaurids worldwide it may
> concluded that, like mosasaurs, elasmosaurids were still widespread and
> diversified during the late(st) Maastrichtian [...]. Even if precise
> stratigraphical extensions are often difficult to obtain for large
> vertebrate remains, the extinction of elasmosaurids at the K/T boundary
> appears to be sudden rather than gradual."

Is this now the accepted view?  Seems just yesterday that they were extinct
before the boundary.