Re: Postorbital processes (& weighting??)

["David Marjanovic" <david.marjanovic@gmx.at>]

----- Original Message -----
From: "Ken Kinman" <kinman@hotmail.com>
Sent: Monday, December 17, 2001 1:10 AM


>       Need to get some things cleared up here.  {Sinornis + Passer} =
> Euornithes (not Ornithothoraces).

Nope. Euornithes Sereno 1998 is {Neornithes > *Sinornis*}, while
Enantiornithes sensu Sereno 1998 is {*Sinornis* > Neornithes}. He writes the
position of *S.* is so well known that he uses it rather than *Enantiornis*,
or something like that.

>       Ornithothoraces is presently defined as {Iberomesornis + Passer}.

True, sorry. But probably Sereno uses *Sinornis* instead, haven't checked,
and at present that's the same clade.

> David asked in his original post if there are any "other ornithothoracines
> except confuciusornithids" with the process.

Aaaaah! Sorry! Caught me on that! I was talking about {*Passer >
*Confuciusornis*}, so Pygostylia instead of Ornithothoraces is correct
above.

> This phrase seemed to imply he
> believed confuciusornithids to be ornithothoracines (making the latter
> equivalent to Pygostylia).  This didn't surprised me

It should have :-)

> since some phylogenies
> would make Ornithothoraces even more inclusive than Pygostylia.

Such as the description of *Confuciusornis* (Hou et al. 1995) which put it
next to *Gobipteryx*. Nothing of the sort is still in use.

> So just to
> clarify, I now assume David meant to say "other pygostylians except
> confuciusornithids".

Yes.

>      But my position will still be pretty much the same.  I would not be
> surprised if the said process was lost independently three, four, or even
> more times.  Multiple losses (even it takes more steps) can be more
> "parsimonious" if a reversal (reacquisition) is very difficult (that's
where
> function could be important).

The question here is whether the reversal is in fact "very difficult". I
don't think so.

>      Of course, that means I am suggesting some possible "character
> weighting" might be warranted,

Sometimes it is IMHO. But it's very difficult in morphology (less so in the
molecular world).