Re: New alvarezsaurid

["John V Jackson" <jjackson@interalpha.co.uk>]

-----Original Message--From: Jaime Headden Date: 02 April 1998 07:52

>And both *Archeopteryx* and *Dromaeosaurus* shared a common ancestor
>with *Oviraptor,*

If you non-BCF'ers think that, it must have been an extraordinarilly flight
adapted precursor, which would actually make BCF more likely!


Matt Troutman wrote:

>    Alvarezsaurs show hardly any unifying characters with
> enantiornithines ( reverse scapulacoracoid articulation, etc ).

You just migt be right on that one - I was taking a bit of a flyer there
since I haven't taken a close look at Alv.  But even a brief glance shows
that it is unwise to base any relational propositions between Alv. and
anything with half-way normal arms/wings, based on the arms/shoulders.
However, you are wrong on. . .

> "Rahona" is not a link between Archy and dromaeosaurs. Archaeopteryx is
> too specialized and birdlike to be ancestral to dromaeosaurs.

. . .for the old reason of relying on flight specific features as useful
phylogenetic markers.



Tracy said she'd heard her fair share of paleontologists say that they
didn't like how
 the cladogram came out and they had to tweak it to get what they wanted.
 That would obviously be a great temptation to anyone, me included, though I
would be even more tempted to put the whole Wizard of Oz screen out the
window!  I very nearly posted the following mail for April 1:

"Just released - New Multi-Facility Cladogenesis Package by Vorpal
Enterprises !
Features include:
     Camera-ready diagram production, complete with library illustrations;
     Suggested phrases and key words for every aspect of the structure;
        and - Unique to this package -
     New *Edificing* facility - just type in your preferred structure,
       and the system will scan all the data until it finds a subset to
justify it!
       (or will prompt you for more data until it can.)"

Sadly, I also considered actually going ahead and writing it.  Even more
sadly, I still think there would be a big market for it!


Matt wrote:

>    Oviraptorosaurs . . . lack all of the characters that . . . define
birds.  <

They've got the extraordinary bird forelimb structure, and I'll bet they (or
their ancestors) had proper feathers too!  That will be  good enough for me
when we get them.  (I'm reluctant to mention their uncinants since I think
it was you that told me about them, and I down want to throw them back at
you!)

Thank you for your refs on paedomorphism and flightlessness, which I will
look up as far as I can, though I know they will only say what you've been
saying.  Actually when I said *written* I was thinking more in the *fated*
sense.

JJ

"Is it better to be half-assed or biased?"   Well, I'm experimenting with
both at the moment - I think that's fair, and scientifically fairly sound!