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Re: Jouve's and Tacquet's Ctenochasma sp.




Nick Pharris wrote:

> Quoting david peters <davidrpeters@earthlink.net>:
>
> > Stephane Jouvé asked that I post this letter to the dinosaur list.
> >
> > With all honors, I do so now without comment, other two preliminary notes:
> >
> > 1) a phylogenetic analysis of every decent specimen in the inventory of the
> > Pterosauria reveals that that the Pterodactyloidea is paraphyletic,
>
> Er, you mean polyphyletic.
>
> > with
> > separate origins for the Ctenochasmatoidea, etc. and the Azhdarchidae, etc.
> > from various Dorygnathus specimens; and the Cycnorhamphidae +
> > Ornithocheirid[ae], etc. and Pterodactylidae + Germanodactylidae etc.
> > etc. from various Scaphognathus (themselves derived from basal Dorygnathus).
>
> Paraphyletic is what _Dorygnathus_ and _Scaphognathus_ would be, under this
> scenario.
>
> And let me express my amazement (and skepticism) that you've been able to 
> prove
> that all these higher-level clades are actually descendants of particular,
> known specimens.

I was surprised too. But PAUP did all the work.  I just put more ingrediants in
than other cooks.

The kicker is, you can line up the reconstructions, and, as in synapsids to
mammals, theropods to birds, etc. you can see the spectrum of gradual change, 
with
a few branches tentatively jutting out toward other unknown lineages.

Frankly, with as much praise as was heeped on cladistics in the 90s, and with no
other analysis able to solve the problem of pterosaur interrelations, and 
finally
with the precedent of The Dinosaur Renaissance, I don't see why a rethinking of
this old problem is meeting such resistance without testing.

And you're right about polyphyletic. Thank you.

>
>
> Nick Pharris
> Ph.D. Candidate
> Department of Linguistics
> University of Michigan