Re: Avaceratops and Ceratops (was RE: First International Phylogenetic Nom...)

[Tim Williams <twilliams_alpha@hotmail.com>]

Paul Penkalski wrote:

> Here's my 2 cents on this. In our 1999 paper, Dodson and i concluded that 
> _Ceratops_ is a nomen dubium because the material - essentially just two 
> horncores - is insufficient for diagnosis. So even if Avaceratops were 
> really Ceratops, it is doubtful one would ever be able to demonstrate it. 
> (at
> least not in this lifetime). Still, it's a fun puzzle to play with.

Thanks for the reply, Paul.  It's nice to get info straight from the horse's 
mouth (so to speak).

Yeah, _Ceratops montanus_ is toast.  The type material (two postorbital 
horncores, occipital condyle is probably non-diagnostic.  The horncores of 
_Ceratops_ are a little strange in the way they twist outwards, but the 
range of variation in horncores within a neoceratopsian species seems fairly 
high anyway.  _C. montanus_ is probably best regarded as a _nomen dubium_.

However, there is a glimmer of a chance that the genus _Ceratops_ could be 
salvaged, if topotypic material is found.  I keep on hearing that the type 
locality was re-located, and/or ceratopsian material from the Milk River 
Formation might be referrable to _Ceratops montanus_.  I don't know anything 
more than this.



Tim

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