The two part explanation of why the dicosaurs went extinct was a series of discussion lines that Dave Raup included in his classic text "Extinction, Bad Luck, or bad genes". RAup and another paleo dude named Sepkoski developed a timeline of extinction that showed that extinction events were spread about in about 26 million year cycles on the earth.
His explanation above was an attempt at humor in a book that ued lots of gambling statistics and looks at the fossil record to develop a simple thesis that. "If you are alive now, chances are almost 99.999% that your own species will go extinct".
RAup used extinction as a great exemplar of how "Niches" are lweft open periodically so that new species can adapt to a changing environment.
THIS from Wiki:
David M. Raup is a University of Chicago paleontologist. Raup studied the fossil record and the diversity of life on Earth. Raup contributed to the knowledge of extinction events along with his colleague Jack Sepkoski. They suggested that the extinction of dinosaurs 65 mya was part of a cycle of mass extinctions that may have occurred every 26 million years.
In addition to his time at the University of Chicago, Raup has taught at Caltech, Johns Hopkins, and the University of Rochester. He was also a curator and Dean of Science at the Field Museum of Natural History in Chicago as well as a visiting professor in Germany at Tübingen and on the faculty of the College of the Virgin Islands. Raup was heavily involved through his career in joint programs with biology and in promoting training of paleontologists in modern marine environments. In 1994, he retired to Washington Island in northern Lake Michigan. Currently, he assists the Santa Fe Institute to develop methods and approaches to dealing with the evolutionary exploration of morphospace.
1Dinosaurs were a bad idea to begin with
2They had gone on quite long enough.
Who says? And why?[/quote]
There's no response that would be forthcoming, it was just an attempt to provide some smartassness (especially using a numbered sequence, which is a very popular way of itemizing things for scientists to evaluate at symposia. Raups comments became rather popular among humor starved paleontologists so that some wag even started printing tee shirts and several kids were sporting them .
summary: I wouldnt think too deeply about it. DAve Raup was always entertaining at talks about extinction.