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Re: _Turanoceratops tardabilis_



On Sun, 25 Feb 1996 Dinogeorge@aol.com wrote:


> (Yes, Protoceratopidae _sensu lato_ is paraphyletic, but the known genera
> seem to form a monophyletic clade within this Protoceratopidae _sensu lato_,
> and most authors refer only to that clade as Protoceratopidae, keeping things
> monophyletic. It's the sister group of Ceratopidae within Neoceratopia.
> _Turanoceratops_ might be a neoceratopian that is neither protoceratopid nor
> ceratopid but located along the stem of Ceratopidae.)

I'm a little confused by the above statement. How can all known members 
of a taxon form a monophyletic clade yet the taxon still be paraphyletic? 
Unless of course you are intending to place any future discoveries of 
"stem" ceratopids or neoceratopians into Protoceratopidae. What would be 
the justification for this? Wouldn't it be simpler to place stem 
ceratopids in Ceratopidae and stem neoceratopians a plesions outside of 
Neoceratopia (if Neoceratopia has a node based definition) or outside of 
Ceratopidae + Protoceratopidae, within the Neoceratopia (if a stem based 
definition is used).

Adam Yates