RE: Question(s) about Cladistics and PhyloCode

[Christopher Taylor <gerarus@westnet.com.au>]

> 2. Is it really wise to declare taxa based on scrappy remains nomia
dubia 
> because they lack a single unique derived character even before we
have 
> stabil (or at least somewhat exhaustive) definitions  of the taxa they
most 
> closely resemble?

    (Pedantic moment) Do you mean 'definition' or 'description'? A
description gives an account of a taxon's characters in general, while a
definition (or diagnosis) would give specifically those features that
distinguish the taxon from others.
    Also, whether a taxon has been adequately defined is always a matter
of context - a taxon that can be described in detail may still be
dubious if the specific characters that are significant in
distinguishing it from other taxa are not available, while a taxon that
is known from only a few characters may be identifiable if those
characters are distinct from any other taxon.

> I recently read an article were three taxa were declared nomia dubia 
> eventhough their closest suspected relative lacks a modern
description. 
> While the results of the article were formally correct under the rules
of 
> cladistics and the present knowledge of the clade (really a more
inclusive 
> clade), the taxa might need to be reinstated when the knowledge of the
clade 
> improves.

So it goes. It's worth while keeping in mind that 'nomen dubium' is an
informal designation only, and names declared nomina dubia remain
available, with the potential to come back into use with further study.
Declaring a name a nomen dubium simply means that the author is
currently unable to distinguish the taxon in question.

    Cheers,

        Christopher Taylor

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