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Re: Platecarpus tympaniticus - how to analyze a nomen dubium



On 22 September 2010 16:54, T. Michael Keesey <keesey@gmail.com> wrote:
> On Wed, Sep 22, 2010 at 2:57 AM, Mike Taylor <mike@indexdata.com> wrote:
>>
>> It's worse than you think.  So far as the PhyloCode is concerned
>> authorship of the rank-based taxon and the homonymous clade are
>> completely separate, so whatever definition I used of Ceratopsia when
>> defining it as a PhyloCode-govered clade, it would be Ceratopsia
>> Taylor 201X.  The code suggests an authority-mentioning scheme that is
>> something like Ceratopsia Taylor 201X [Marsh 1890], which goes some
>> way to towards addressing this.
>
> Now it's my turn to correct you. That was true in the first draft of
> the code, but it has long since been remedied. See Art. 20:
> http://www.ohio.edu/phylocode/art20.html
>
> If you were to convert Ceratopsia Marsh 1890 into a clade name, it
> would be cited in full as Ceratopsia Marsh 1890 [Taylor 201X].

Oh, that's better -- nominal author first, definition author second in
brackets.  Yes, I misremembered the order.  (Should have looked it up
instead of saying "something like ...")

> If I were to then emend the definition, it would be cited in full as
> Ceratopsia Marsh 1890 [Taylor 201X] {Keesey 202X}.
>
> And, lest you think you could get away with "Ceratopsia [Taylor
> 201X]", Art. 20.4 explicitly states, "If the definitional author of a
> converted name is cited, the nominal author of the preexisting name on
> which it is based, if known, must also be cited."
>
>> Worse, there seems to be no way to cite the originator of a specific
>> phylogenetic definition or indeed the first explicit user of the name.
>>  So Marsh used the rank-based family Diplodocidae in 1884, and so is
>> deemed also to have raised the superfamily Diplodocoidea (by the
>> Principle of Coordination); Upchurch first used the name Diplodocoidea
>> in 1995; and Wilson and Sereno defined it phylogenetically as
>> (Diplodocus < Saltasaurus) in their classic 1998 monograph.  But since
>> that definition is not governed by the PhyloCode, it would need
>> re-establishing once the code is enacted.  If I did that, then the
>> resulting name would be Diplodocoidea Taylor 201X [Marsh 1884], and
>> neither Upchurch (1995) nor Wilson and Sereno (1998) would get any of
>> the attribution love.  I think the idea is that the people who first
>> coined a phylogenetic definition should be encouraged to be the ones
>> to redefine it under the PhyloCode, but in the case of authors like
>> Wilson and Sereno who are antagonistic towards the Code and explicitly
>> don't wish to contribute, what can you do?
>
> This is a good point. Perhaps Diplodocoidea Marsh 1884 [Wilson &
> Sereno vide Taylor 201X]?

That's not bad.  I guess if we all use this form, then it'll catch on :-)

>> I suppose the moral of all of this is that we should be less concerned
>> with whose personal name appears after the taxonomic name; in
>> practice, the personal name rarely if ever appears after clade names
>> anyway, so this may be a bit of a red herring.
>
> True. Citations are often used to distinguish homonyms (e.g.,
> Stormbergia Seward 1911 vs. Stormbergia Butler 2005), but the
> PhyloCode doesn't allow homonyms, anyway. (Dirty secret: the ICZN
> allows homonyms across rank groups.)
>
>> I was talking about Ceratopsia, but since you mention Ceratopsidae,
>> there's no reason we shouldn't define it as (Triceratops horridus <-
>> Protoceratops andrewsi, Leptoceratops gracilis), give the etymology as
>> "horned face" (not mentioning Ceratops montanus), and move on.
>>
>> That seems obviously The Right Thing.  The fact that the clade name
>> happens to resemble the name of a dubious genus is neither here nor
>> there.
>
> This would run afoul of Art. 11.7.

I've just argued that I don't think it does.  The wording is that
"when a clade name is converted from a preexisting typified name or is
a new or converted name derived from the stem of a typified name, the
definition of the clade name must use the type species of that
preexisting typified name [...] as an internal specifier", but in the
scenario I outlined, the clade name Ceratopsia woulkd NOT be "derived
from the stem of a typified name" -- it would be derived from the
words for "horned face".