Re: New papers in Geobios (and nomenclatoral gripe)

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

----- Original Message -----
From: "Tim Williams" <twilliams_alpha@hotmail.com>
Sent: Wednesday, June 21, 2006 4:21 PM

> The only way to bypass this situation is to designate a new type species, 
> as
> was done with _Iguanodon_.  The original type species (_I. anglicus_) was 
> a
> nomen dubium, which technically made _Iguanodon_ a nome dubium too.  But
> the ICZN allowed a new type species to be designated (_I. 
> bernissartensis_),
> which 'rescued' the genus _Iguanodon_ from oblivion.  If your premise was
> correct (i.e., a genus is valid even if the type species is specifically
> non-diagnostic), then we would not have had to go to all this trouble for
> _Iguanodon_.

No, this is not the same situation. The problem with *Iguanodon* was that 
there was no way to tell whether *I. anglicus* belonged to the same genus as 
*I. bernissartensis* and *I. atherfieldensis*. In other words, there was a 
risk that the latter two species, which had made a substantial career under 
the name *Iguanodon*, could end up not belonging to *Iguanodon*. To avert 
this risk the ICZN designated *I. bernissartensis* as the neotype of 
*Iguanodon*.

Same with *Coelophysis*: there was a risk that the Ghost Ranch specimens 
could end up not belonging to *Coelophysis*.