Paraphyla nomenclature was Re: Ceratosauria vs. Neotheropoda?

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

>  Oh, and of course option #3: define the groups as paraphyletic using
>  a formal phylogenetic definition.  I know a lot of people have
>  religious objections to this, but I'm not one of them.  For example,
>  I'd be perfectly happy with Proasauropoda = (Sauropodomorpha -
>  Sauropoda) where Sauropodomorpha = (Saltasaurus not Allosaurus) and
>  Sauropoda = (Saltasaurus not Melanorosaurus).

You can already do that, and you'll also be allowed to do it under the 
PhyloCode. All that will be forbidden will be to register such a name 
and thus establish it (so it could compete with other established names 
for precedence).

That's still not enough for you?

You know what?

Let's set up the International Code for Nomenclature of Paraphyla 
(ICNP). Right now.

1. Names must have phylogenetic definitions: one clade minus one or 
several others. Each of these clades must have a definition that would 
be acceptable under the ICPN (the PhyloCode), but those definitions need 
not be established there.
2. Names that are established under the ICPN cannot be established here.

All that's left to do is to convince the other 12 Committee members (I'm 
the 13th) to adopt the mirror image of 2. in the PhyloCode. :-)

>  I've seen paraphyletic taxon names written with an appended asterisk
>  in some contexts (e.g. Colin Tudge's book _The Variety of Life_,
>  which by the way I heartily recommend).  That seems like a reasonable
>  approach.  So: Sauropodomorpha, Prosauropoda*, Sauropoda.  I'm not
>  sold on it, but it seems like an option.

3. Established names {should|must}be marked in writing with {some sort 
of symbol} to distinguish them from clade names and rank-based names.

What that symbol should be is of course a good question. An asterisk 
behind the name will send people looking for a footnote or, worse, an 
endnote. Two asterisks, one on each side, appears to be a common 
convention among German-speaking cladists, but has been overtaken by 
general Internet emphasis. Reverse italics (\ instead of /) are only 
available in some versions of Microsoft Word and, I think, nowhere else...

>  However, in the wrong hands, paraphyletic groupings could spell big
>  trouble.  For example, I can foresee the BANDits resurrecting the
>  Thecodontia as a paraphyletic group that includes the (alleged)
>  ancestors of birds, and claiming the validity of Thecodontia is
>  justified under the rules of phylogenetic taxonomy.

No, because it isn't taxonomy. It's nomenclature. We'd simply have a 
potentially self-destructive name on our hands. :-|

To imply that, because it's possible to take a word and give it a 
definition, that definition must correspond to anything in reality... 
that would be an argument I'd put even past the BANDits. It reminds me 
of those webpages that are entitled "Arguments We Think [people on the 
same ideological side as the authors] Should Not Use", where fairly 
commonly used but incredibly stupid arguments are listed and merely 
ignorant arguments suggested instead. :o) (Find out what ideology I 
mean, google for the phrase, and laugh. And laugh... and laugh...)

>  Paul argued that the practice of avoiding paraphyletic groups was
>  discriminatory, because families such as Iguanodontidae were being
>  penalized simply because they happened to give rise to a "terminal"
>  taxon (Hadrosauridae). However, this is only a big deal if you're
>  hooked on rank-based classification.

Bingo.