Re: Many new references

["Tim Williams" <twilliams_alpha@hotmail.com>]

T. Michael Keesey wrote:

> > while Titanosaurus (indicus) is abandoned as there are 'no valid > 
> diagnostic characters'.
>
> Thus, all the names based on _Titanosaurus_ (_Titanosauridae_,
> _Titanosaurioidea_, _Eutitanosauria_, _Titanosauria_) must include _T. 
> indicus_ (or a neotype species, if one is ever designated) as an internal 
> specifier, or the names should be abandoned.

I agree with Mike.  Unless a neotype is designated for the species _T. 
indicus_, and it can be consequently upheld as a valid (i.e. diagnosable) 
species, then there is little point using the genus _Titanosaurus_ as the 
nominative taxon for higher-level clades.

To further complicate the _Titanosaurus_ situation, some of the Lameta 
material referred by Huene and Matley (1933) to _T. indicus_ indicates a 
very unusual titanosaurian sauropod, which may not belong in the 
Titanosauridae as defined by Salgado (2003).  Huene and Matley (1933) 
believed this material (and the type material for _Antarctosaurus 
septentrionalis_) came from the same horizon as the type caudals for _T. 
indicus_ named by Lydekker.  (Apparently the status of _Titanosaurus_ will 
be addressed in a forthcoming _Syst. Palaeont._ paper.)

The _Titanosurus_/Titanosauridae problem also applies to Hadrosauridae and 
Ceratopsidae, the nominative genera of which are also highly suspect.  Also, 
according to Yates (2003), the type species for _Plateosaurus_ (_P. 
engelhardti_) is also possibly non-diagnostic, meaning a neotype may have to 
be found in order to salvage this genus from the dreaded _nomina dubia_ 
dustbin.  It's worked before for _Allosaurus_, _Iguanodon_ and 
_Scelidosaurus_.




Tim

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