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Re: Were dinosaur ecosystems continent-sized? (resend)



There are two schools of thought on this.
If I were asked (and no one seems to want to ask me ;-), I believe the null 
hypothesis is that, as is the case today, flora/faunal ecosystems were highly 
variable in reasonably large areas.  The question is, what is a "reasonably 
large area"?

Many researchers in geology (which is something I am a bit more familiar with), 
tend to use generalizations as their null hypothesis, pending new information.  
As research advances, the generalizations tend to become less general (first 
null hypothesis:  All batholiths in the western part of Washington State are of 
the same age).  Revised null hypothesis:  Only some batholiths in W. Washington 
are of the same age.  Newest hypothesis:  nearly all batholiths in W. 
Washington are of different geologic ages, within the limits of 
geochronological dating.

I assume that such generalizations in paleontology tend to get "de-generalized" 
over time as well.

Just because North America's Ursus horribilis is found in Asia doesn't mean 
that the snow leopard must therefore be found in North America.

<pb>




---------- Original Message ----------
From: GUY LEAHY <xrciseguy@q.com>
To: Dinosaur Mailing List <dinosaur@usc.edu>
Subject: Were dinosaur ecosystems continent-sized? (resend)
Date: Thu, 22 Apr 2010 18:54:21 -0700


Resent, this time in plain text... :-)
 
According to this analysis, yes:
 
http://www.mcgill.ca/newsroom/news/item/?item_id=116613
 
 http://www.pnas.org/content/early/2010/04/05/0913645107
 
 A couple of problems right off the top:

1. No faunas from Utah, New Mexico or Texas are included in the dataset. 
2. The upper Maastrichtian Scollard fauna is not included, but the lower-middle 
Maastrichtian Horseshoe Canyon fauna is...
  
It's an interesting coincidence in time this appears a few days after the 
publication of a new pachycephalosaur (_Texacephale_), where the authors 
suggest exactly the opposite scenario: 
http://www.sciencedaily.com/releases/2010/04/100419132406.htm
 
Guy Leahy                                         

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