Re: New Cretaceous bird and other papers

["Ken Kinman" <kinman@hotmail.com>]

     Well I certainly agree about the timing problem.   Our ability to 
calibrate "molecular clocks" will eventually be more accurate, but at 
present they are crude estimates that should be taken with a grain of salt.
     I too would bet these families split after K-T, sometime during the 
Paleocene.  We have to be skeptical of such dating, as we are talking about 
molecules evolving, not something as predictable as the number of atoms 
decaying at a constant rate.
     If these families did split later in the Paleocene, we certainly won't 
be confined to Antarctica for evidence, so we shouldn't let a molecular 
estimate like this dissuade us from searching for fossil evidence in places 
other than just Antarctica.
         ------ Cheers,  Ken
***************************************
David Marjanovic wrote:
> :-) I'll try -- I'll just question the reliability of molecular clock 
> estimates that cross the times of mass extinctions. Also, when you take the 
> lower end of the range, you might end up with Accipitridae and Falconidae 
> separating just after the K-T -- as part of the Paleocene neornithine 
> radiation. Well, who knows. Let's find a fossils. Unfortunately most will 
> be in Antarctica respectively eroded off it by glaciers. :.-(




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