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Re: Why Did Mammals Survive the 'K/T Extinction'?

On Wed, Feb 3rd, 2010 at 3:13 PM, Paul Heinrich <oxytropidoceras@cox.net> wrote:

> Probing Question: Why did mammals survive the 'K/T extinction'?
> Thursday by Nick Bascom, Research/Penn State,  January 28, 2010
> http://live.psu.edu/story/44042
> Why Did Mammals Survive the 'K/T Extinction'? Science Daily
> January 31, 2010,
> http://www.sciencedaily.com/releases/2010/01/100131221348.htm

Studies in the areas that were wiped clean of life around Mount St.Helens 
indicated that 
insect/arachnid populations are amongst the first to recolonise devastated 
areas. Even before plant 
life begins to appear, an ouroboros-like insect/arachnid ecosystem can appear 
due to them 
constantly flying or being blown into the barren areas, surviving on the only 
edible resource 
availalel - each other.

If this was also the case in prehistory, then small insectivores may have been 
more likely to 
recolonise such devastated areas once arthropod communities took hold. This may 
have given 
small mammals and birds a slight edge, since they wouldn't have to hold out 
nearly as long for a 
predatable ecosystem to redevelop as larger predators or herbivores would have.

Certainly in modern deserts with little or no vegetation cover, small mammals 
and birds tend to be 
the most abundant of endotherms (although they're still outnumbered by reptiles 
and arthropods).


Dann Pigdon
GIS Specialist                         Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj