Re: The Papers That Ate Cincinnati

["T. Michael Keesey" <keesey@gmail.com>]

On 5/5/07, don ohmes <d_ohmes@yahoo.com> wrote:
> ---- If the organisms in Mammalia remain the same, and the word is the same, then what is meant by "conversion"?

Good question. Basically it means converting the name from a
rank-based taxonomic name with no explicit definition (diagnoses and
composition lists don't count) to a phylogenetic name associated with
an explicit definition.

It's not a given that "the organisms remain the same" because, outside
of phylogenetic nomenclature, there are no explicit definitions (that
I am aware of, anyway). For example, Class Mammalia has variably
included or excluded certain extinct taxa (e.g., docodonts).
Converting the name from a class name to a clade name under PhyloCode
would require an explicit definition (e.g., the final common ancestor
of _Ornithorhynchus anatinus_ and _Homo sapiens_, and all descendants
thereof). You wouldn't really be able to equate Clade _Mammalia_ with
Class Mammalia because the latter is not explicitly defined.

--
Mike Keesey