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Re: New papers in Geobios (and nomenclatoral gripe)

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.



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