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Re: _Turanoceratops tardabilis_



On Mon, 26 Feb 1996, Adam Yates wrote:

> 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? 

Welcome to the weird world of Olshevskian logic!

> 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).

Hmmm.  This sounds suspiciously familiar.  Ah, Yes.  That's it.  I spent 
about a week going over this very sort of argument with George regarding 
herrerasaurs, theropods, and hypothetical stem sarcodinosaurs.

I agree with you.  Basal neoceratopians, were they ever to be found and 
recognized as such, could not be placed _in_ the Neoceratopsidae if one 
defines this as, say, all descendants of the last common ancestor 
of _Leptoceratops_ and _Triceratops_, because the more basal neoceratopians 
would not have been descended from that common ancestor!  

Even if one uses the old character-based system, basal neoceratopsians 
would be excluded because they would necessarily lack certain features 
shared by Ceratopidae and Prtoceratopidae.

> Adam Yates  

Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447
(206)535-8204
PharriNJ@PLU.edu

"If you can't convince them, confuse them." -- Harry S. Truman