Re: DEFENDING MODERN BIOLOGY

[Stanley Friesen <sarima@friesen.net>]

At 12:06 PM 6/21/00 -0400, Timothy Williams wrote:

> Now that you mention it, it WAS a polyphyletic trash-can.  The Thecodontia 
> became a receptacle for any Triassic reptile that appeared to be an 
> archosaur and did not appear to be a dinosaur, crocodilian or pterosaur.
> I've seen _Longisquama_, _Sharovipteryx_ (_Podopteryx_) and _Hupehsuchus_ 
> all shoehorned into the Thecodontia.

Saying this makes _Thecodontia_ polyphyletic assumes that one accepts the 
cladograms that put these animals in or near the Prolacertiformes.  Just 
about everybody I know of who put them in _Thecondontia_ believed they were 
shared a closer common ancestor with _Proterosuchus_ than with any 
prolacertiform.  Given such a family tree, a Thecodontia including them is 
paraphyletic, not polyphyletic.

I agree that recent evidence favors a prolacertiform position for these 
genera.  But any taxonomist of a Mayrian stripe would take this as a 
sufficient reason to *remove* them from _Thecodontia_.

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May the peace of God be with you.         sarima@ix.netcom.com