Re: Cretaceous taeniodont

["Tim Williams" <twilliams_alpha@hotmail.com>]

John Bois wrote:

> Apart from the whole asteroid thing, evidence in support of this is:
> - decrease in pterosaur diversity (prime suspects being birds)
> - eradication of old bird clade by new birds (unless one accepts
> Feduccia's lucky survivor of shorebirds theory)

I think one can dispute Feduccia's transitional shorebird theory and 
disagree with your "evidence" at the same time.  BTW, your assertion that 
"new birds" eradicated "old birds" is a hypothesis, not evidence.  You'll 
have to compile data to support this hypothesis before you can use it to 
support other hypotheses.  (Also, what is an "old bird".  If you mean 
enantiornithines and/or basal ornithurines, these appear to have been much 
more successful in the LK than our modern friends, the neornithines.)

> - decrease in dino diversity before the K/T

This is based on late K North America alone, right?

> - increase in mammal size just before the K/T (if this is demonstrated)

"If" indeed.  If this can be demonstrated, then it qualifies as "evidence".  
Until then...

That reminds me, what were the ecological niches of these bigger Mesozoic 
mammals (_Didelphodon vorax_, _Cimolestes magnus_, _Schowalteria clemensi_)? 
 Can we be certain that they actually competed with dinosaurs?

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