On Sun, 5 Dec 1999 EvMick@aol.com wrote:
My feel of the state of the knowledge at this point is that there
is fairly strong evidence that the dinosaurs ended quite abruptly
(based on fossil collections in South Dakota over the last year).
Before this work, there had been some discussion that volcanic activity over an extended period could have contributed to a gradual decline.
So, my impression is that currently the money is on the dinosaurs buying the farm on the impact of the meteor (comet???) in Mexico.
At the same time there are several other extinctions that may have been involved in massive climate changes due to CO2 production in India or Siberia *and* other events that may have been triggered by massive releases of the methane hydrates sequestered on the ocean floors. The geologists, paleontologists and astronomers are going to have a lot of fun pinning these things down in a concrete way as far as dates, % of species extincted and long term side effects over the next decade or two. This evidence they collect is going to have to be reconciled head-to-head with the evidence that the biologists gather from genome evolution. When the dust settles we may have a relatively good history of the development of life.