[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]


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_.

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