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Re: Fossil Discovery Threatens Theory of Birds' Evolution



In a message dated 6/25/00 12:05:38 AM Pacific Daylight Time, 
dbensen@gotnet.net writes:

> >>The definition of "mammal" has changed in the last decade or so. How do 
> you know that a live Olyagopolis would look like a reptile?<<
>  Isn't mammals' diagnostic feature (besides mummeries, I mean), their 
single 
> lower jawbone and the presence of ear bones?

Not according to phylogenetic taxonomists.  The "diagnostic feature" for a 
mammal, if you're a PT practitioner, is that it is descended from (or is) the 
common ancestor of all living mammals.

Personally, I'd prefer the apomorphy-based definition: Mammalia = {the first 
ancestor of modern mammals to possess a single lower jawbone + all of its 
descendents}; but, alas, it was not to be.

Nick P.