Re: New papers in Geobios (and nomenclatoral gripe)

[Tim Williams <twilliams_alpha@hotmail.com>]

David Marjanovic wrote:

> 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*.

Yes, because _I. anglicus_ (originally _I. anglicum_) was a nomen dubium!  
Here's what Charig and Chapman (1998) said in their petition to the ICZN 
(Case 3037)...

"At present _Iguanodon anglicus_ Holl, 1829 is the valid type species for 
_Iguanodon_ but this is known only from fragmentary and non-associated teeth 
which show a complete lack of diagnostic characters." (p.99)

Charig and Chapman (1998) mention both _I. bernissartensis_ and _I.  
atherfieldensis_ in their petition, but only in the context of mulling over 
which of these should be put forward as as the new _Iguanodon_ type species.

> 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*.

Given that the original type species (_I. anglicus_) was based on 
specifically non-diagnostic material, this was a great risk indeed.  Without 
a taxonomically valid type species, NO other species could be assigned to 
_Iguanodon_.  Furthermore, the current uncertainty surrounding exactly how 
many  species actually belong in the genus _Iguanodon_ would have added a 
further complication, if _I. anglicus_ had remained as the type species.

Cheers

Tim

P.S. For the benefit of "No Way", this is a discussion on NOMENCLATURE not 
CLADISTICS.