Re: Suchosaurus, Baryonyx and Martinavis

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

Responses to several posts below:

On 10/2/07, Tim Williams <twilliams_alpha@hotmail.com> wrote:
>
> > But isn't that a separate matter, to do with the selection of
> > neotypes? The only instances I see in the ICZN of the word "dubium" is
> > in articles about the selection of a neotype.
>
> The selection of neotypes is a separate issue; here the ICZN cites the term 
> nomen dubium explicitly. However, the principle behind a nomen dubium comes 
> up elsewhere implicity - specially with this hierarchial typification issue.

Well, as long as it's implicit, can we really know what it means?

> > But it is taxonomically valid, since it was validly published, isn't it?
>
> If a name is validly published, it is *nomenclaturally* valid, I would say. 
> Nomenclatural validity is determined by the ICZN, and is objective (at least 
> in theory...).
>
> Taxonomic validity, on the other hand, is entirely subjective.

Okay, I see the distinction.

But in some instances the ICZN just says "valid", without specifying
whether it means "nomenclaturally valid", "taxonomically valid", or
both.

> I wondered about that too. But the principle of hierarchial typification 
> should also apply to when a nominal species is a nomen dubium.

I guess that's the real question, but I don't see that the code itself
makes it clear one way or the other. I could, of course, be missing
something.

> > I would disagree in the case of eponymous names. _Ceratops montanus_
> > might not be well-known, but it should not be permissible for it to be
> > outside of _Ceratopsidae_.
>
> Yep. And there's the rub. It is often difficult to assign a fragmentary taxon 
> to a given family. How confident are you (or anybody) that _Ceratops 
> montanus_ can be assigned to Ceratopsidae? All we have for _Ceratops 
> montanus_ are an occipital condyle and a pair of horn cores.

Well, if you define _Ceratopsidae_ as Clade(_Ceratops montanus_ +
_Chasmosaurus belli_ + _Centrosaurus apertus_), you can be *extremely*
confident that _C. montanus_ belongs. :)

Incidentally, the latest version of the PhyloCode allows for
emendations of definitions to be published in some cases where strict
adherence to the definition would result in a disruptive usage. See
Arts. 15.8 - 15.5 (http://www.ohiou.edu/phylocode/art15.html#art15.8).
I wonder if this might ever conflict with Art. 11.7....

> > Isn't _Deinodon_ specifically a nomen oblitum, though?
>
> I wasn't aware of this. To be a nomen oblitum a name must not appear in the 
> literature for 50 years after its publication, and I don't think _Deinodon_ 
> qualifies.

Sorry, I was thinking of _Manospondylus_! Never mind.

David Marjanovic wrote:
> Go, Torvosauroidea! It's by far the best name of the three anyway. =8-)

Paul's (1988) "Intertheropoda" is actually not far off in terms of
content, although 1) it was meant as a paraphyletic grade, 2) it did
not include spinosaurids (which were thought to be coelophysoids), and
3) it included abelisaurids (which were thought to be close to
_Megalosaurus_ [=_Torvosaurus]).

Mike Taylor wrote:
> Sometimes it seems as though people are deliberately looking for
> points of conflict between the codes.

I know I am! How else can we eliminate (or at least diminish) those
points of conflict before the PhyloCode is put into action?

> They work together, not against each other.

That is the idea.

> I still say that "converting" genera into clades is a category
> mistake.  They are much better left as they are.

Well, you may have a point insofar as Mesozoic vertebrate paleontology
is concerned (although I'm still not sure I agree). But there are
fields out there (botany, entomology, etc.) where a genus might
actually include more than one species -- sometimes even hundreds of
species. Many of those genera are just as good candidates for
conversion as any familial (or even ordinal) vertebrate taxon.

PhyloCode's new Art. 21 at least has provisions for using unconverted
genera, which is a tacit way of saying, "Hey, you don't have to
convert them *all*."

> (Better still would
> be a world in which genera had never been any more important than
> families and other ranks, that is to say, a world without the
> binomial, which is what gives genera their undue influence.)

Agreed! But ... too late.

-- 
T. Michael Keesey
Director of Technology
Exopolis, Inc.
2894 Rowena Avenue Ste. B
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