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Re: Ceratops (was RE: Glishades ericksoni, ...)



 Of course there's nothing stopping someone from including _Ceratops
 montanus_ in a phylogenetic analysis.  But this is not the same as
 saying that there is a *good* reason for including _Ceratops
 montanus_ in a phylogenetic analysis.

 Your suggestion is just special pleading.  _Ceratops_ is the
 name-bearing genus for the Ceratopsidae, and therefore you are
 pretending it's a useful OTU for a phylogenetic analysis.  But it
 isn't.  The type material of _Ceratops montanus_ could belong to any
 number of derived, brow-horned ceratopsians - including (as noted by
 Ryan, 2007) _Albertaceratops_.  In fact, decent cranial material that
 was thought by Trexler and Sweeney (1995) to belong to _Ceratops
 montanus_ was later assigned to _Albertaceratops_.

 Including a deliberately phoney OTU like _Ceratops_ in a phylogenetic
 analysis alongside valid OTUs (like _Albertaceratops_) defeats the
 entire purpose of a phylogenetic analysis, which is to establish
 relationships among taxa.

It's indeed a bad idea to include OTUs that are possibly paraphyletic with respect to other OTUs in the same data matrix.

Of course there's an easy way to get around this: make a specimen-level analysis, and put *Ceratops* in.