RE: Correction/update #3 - Mesozoic dinosaur species)

[Tim Williams <twilliams_alpha@hotmail.com>]

Mike Taylor wrote:

> I admit that when I first saw the word "rebbachisauroid" in the
> abstract I was a bit puzzled as to what that taxon might refer to.  It
> would be great to know what Sebastian's motivation was -- IIRC, he
> does read this list so maybe he'll chip in.

I get the distinct impression that the new name "Rebbachisauroidea" was 
intended to highlight the diverse and speciose nature of the rebbachisaurs.  
> From that perspective, a new name is unnecessary, since PN is blind to the 
Linnaean practice of using ranks to denote (or connote) the perceived 
relative success of groups.  Rebbachisauridae was more than sufficient for 
PN purposes.

> Having seen the
> definition I admit I am at a loss to see what it would bring to the
> party, even were it not for the problem of its being a subset of the
> coordinated family-level taxon.

To give a contrary example, you can see why the authors who named and 
described _Turiasaurus_ avoided coining a family-level taxon for it and its 
nearest relatives.  Instead, they opted for "Turiasauria", which sidesteps 
any and all entanglements with the ICZN.  Similarly, with the problems 
surrounding the name Titanosauridae, Wilson and Upchurch (2003) chose to 
erect a clade called Lithostrotia rather than a new family-level taxon.  
Rebbachisauroidea, on the other hand, is seriously looking for trouble.

Cheers

Tim

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