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Re: Theories on the extinction of dinosaurs
On Sat, 20 Nov 1999 Dinogeorge@aol.com wrote:
> Science that has the Sereno et al sauropod article also has a feature [p.
> 1281] on the extinction and the incidence of dinosaur fossils below and above
> the clay: at a mere 1.8 meters below the clay is the last known dinosaur,
> represented by a Triceratops bone; above the clay, zilch dinosaurian--the
> workers found >no< gradual extinction). The question of >why< it happened to
> be fully sufficient at that time is a different question peripherally related
> to the extinction.
Does this refer to the Lillegraven and Eberle paper? If so, I disagree
with your conclusion. So many coincidences seemed to have occurred at
this time, I think you have biased one over the others. For example, as
noted in the L and E paper, there was an important immigration of mammals
"just at the time" non-avian dinosaurs became extinct. On the other hand,
L and E report no evidence of iridium (I don't know if they tested). So,
evidence of new mammals (admitedly, only conylarths), no evidence of
impact. Additionally, there is zero evidence that _any_ impact _ever_
caused _any_ extinctions, direct evidence, I mean. Mammals are proven
enemies of large flightless birds. Surely they have earned the right to
be considered a prime suspect.