RE: Ceratops (was RE: Pterosaur diversity (was: Re: Waimanu))

[Tim Williams <twilliams_alpha@hotmail.com>]

Mike Taylor wrote:

> ... as I explicitly did (see above).  But is this really something we have 
> a choice about?  I know that people do diagnose taxa from non-type 
> specimens, but it's not really on ... is it?  Or is it?

This is more a product of history.  Lydekker based _Titanosaurus indicus_ on 
two caudals and a femur (subsequently removed, because it came from a 
different stratum).  Thus, these two caudals became the type specimen for 
_T. indicus_.  But, if he had known about the rest of the titanosaur 
material from the Bara Simla type horizon, the type material for _T. 
indicus_ might have included at least some of these bones too (most of which 
were later described by Huene and Matley).  It's not Lydekker's fault that 
the two caudals were the _Titanosaurus_ bones he first clapped eyes on.  
Now, if all the titanosaur material from the type horizon does belong to a 
single individual or species, then it doesn't matter what the type material 
is, because all this material can be combined into a hypodigm that can form 
the basis for a diagnosis.

> To clarify, the thing I feel queasy about is not that Titanosauria is still 
> OK (and please stop messing with my mind my introducing non-sauropod 
> examples :-) -- it's that different rules seem to govern
> Titanosauria and Titanosauridae.  It's the magic in those four letters 
> "idae" that offends me.

This is a rather peculiar quirk.  ICZN rules supreme when it comes to 
species, genera and family-level taxa; but every other taxon is carte 
blanche.  It's bewildering, I know.  This is where my fantasy comes in.  No, 
not the Jessica Alba/whipped cream one - the one involving stripping the 
ICZN of any jurisdiction over anything other than genera and species (and 
subgenera and subspecies too, I guess).

> Truly, "idae" is a four-letter word.

I think it is appropriate to ensure that the name-giving (eponymous) genus 
is retained in a family.

> Really?  There is nothing in the PhyloCode itself that makes a special case 
> of "idae" (nor for any other spelling convention).

I tried to make a case for why '-idae' should be treated differently...

http://dml.cmnh.org/2005Dec/msg00396.html

> Aha!  So you're OK with genera continuing to exist, and be governed by the 
> ICZN?  (I thought I was out on a limb there.)

Perfectly.  Just "hands off" everything above that.  Again, just a 
fantasy...

Cheers

Tim