John, But we weren't really discussing what caused the extinctions per se (the impact scenario is now pretty widely accepted as a given). So I do agree that answering that question is much simpler. We were addressing the more difficult question of why some groups were able to avoid extinction in spite of the devastation caused by the impact. To that question there are no single, simple answers. As for megapodes, they are the sister group to all other galliforms, so there's a pretty good chance ancestral galliforms were mound builders. It also provides a pretty good explanation why megapodes are the most precocial of all living birds, and a reason why they were among the few surviving bird lines after K-T. -----Ken Kinman *********************************************************
From: John Bois <jbois@umd5.umd.edu> To: Ken Kinman <kinman@hotmail.com> CC: dinosaur@usc.edu Subject: RE: Subterranean strategies Date: Wed, 18 Jul 2001 18:03:09 -0400 (EDT)
On Wed, 18 Jul 2001, Ken Kinman wrote:
> A single megapode-like species may have survived because > of buried eggs,
Birds burying eggs is exceedingly rare. In all extant species it is probably a derived behavior.
> Anyway, the fact that tinamous and > megapodes live in the southern hemisphere is probably no coincidence. > Geographic location was clearly another big factor, and other variables as > well, so there are no single, simple answers.
No simple answers? "A bolide crashed into the planet and caused effects--whatever they were--that caused the extinction of every species that disappeared at that time--whoever they were." This is a simple answer.
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