Re: Question(s) about Cladistics and PhyloCode

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

> If it turns out that dromaeosaurids, troodontids, oviraptorosaurs, etc are
> actually secondarily flightless and/or closer to modern birds than is
> _Archaeopteryx_, then I have no problem calling these theropods "birds".

Lots of other people will -- and even if they won't consciously have a 
problem, they'll still have it unconsciously and therefore misuse the name 
over and over again.

> I absolutely adore the ancient Romans, but I don't think their vernacular
> concept of "bird" should influence our phylogenetic definition of the 
> clade
> Aves.

I'm talking of _our_ vernacular concept. We get the chance to approximate 
the scientific concept to our vernacular one, so why not do it?

> > The simplest way to avoid this problem, IMHO, is to give Aves a stem-based
> > definition with dromaeosaurids, troodontids, oviraptorosaurs etc. as
> > external anchors.
>
> Even if it means excluding _Archaeopteryx_ from Aves?

Yes, even then. It will still keep all manner of things from 
*Confuciusornis* to *Ichthyornis*, and probably *Sapeornis*, in Aves, and 
*Archaeopteryx* has already figured prominently (from PDW onwards) in 
phylogenetic hypotheses that placed it far away from all other traditional 
birds. Rather lose one than lose almost all (crown-group) or gain 
*Achillobator* (Archie node, if we're unlucky).