RE:

["Williams, Tim" <TiJaWi@agron.iastate.edu>]

> You'd also have to consider the fact that something that would affect 
> some dinosaurs would have no effect on others (similar to modern 
> diseases in various populations of animals today). The Black Plague 
> doesn't seem to do much to rats that carry the fleas...

Actually, not true.  Rats are also killed by the plague-causing bacterium
_Yersinia pestis_.  During the Black Plague, the urban rat population of
Europe was being killed off at a rapid rate due to _Yersinia_ infection.
It's only because its natural host was declining that the rat flea resorted
to biting other mammals - including humans - and therefore passed the
bacteria on to them.  Rats are not the natural host for the palgue
bacterium; they were victims too (though it's hard to feel sorry for them.)
If rats didn't succumb to the bacteria, then we may not have had the Black
Death.  


Jura wrote:

> The most popular non-dinosaurian reptiles to go extinct were the marine 
> reptiles: the plesiosaurs and the mosasaurs. 

And which were the most *unpopular* non-dinosaurian reptiles?   :-)

> In the air, pterosaurs were another large group to disappear. On an 
> interesting (if not entirely arguable) note, crocodilians, lizards, 
> snakes, turtles, mammals and birds seemed to have come through the 
> extinction pretty well.

I don't think 'pretty well' is entirely accurate.  These groups certainly
survived, and placentals/eutherians seem to have been much less affected
than other groups.  But many reptile (apart from dinosaurs), mammal and
avian groups were decimated at the K/T boundary, or went extinct altogether.
I don't think we know enough about the late K neornithine record to gauge
how they responded to the K/T event.




Tim



----------------------------------------------------------- 


Timothy J. Williams, Ph.D. 

USDA-ARS Researcher 
Agronomy Hall 
Iowa State University 
Ames IA 50014 

Phone: 515 294 9233 
Fax:   515 294 9359