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Ceratops analyzed in the Sampson et al. (2010) matrix



With all of this discussion of Ceratops lately, isn't it about time someone do 
some science to solve the question of what it is?  The newly published paper by 
Sampson et al. (2010) describing Utahceratops and Kosmoceratops includes the 
largest ceratopsid analysis to date.  It also includes both long-horned basal 
ceratopsomorphs Zuniceratops and Turanoceratops and the long-horned basal 
centrosaurine Albertaceratops.  Ceratops could be coded for 7 of the 148 
characters.  It emerges as the sister taxon of Utahceratops within 
'chasmosaurine' ceratopsids.  Thus there is no difficulty defining Ceratopsidae 
or Ceratopsinae based on Ceratops.

Relevent characters include-
- Supraorbital horn sinus enters postorbital, which is only present in 
ceratopsids.
- Supraorbital horn core centered posterodorsal to orbit, broad base with 
posterior margin of supraorbital horncore extending well behind posterior 
orbit, which is only present in Pachyrhinosaurus, Utahceratops and the 
Anchiceratops+Triceratops clade.
- Supraorbital horn core dorsolaterally directed, which is shared with 
'chasmosaurines' more derived than Chasmosaurus, but reversed in Triceratops 
sensu lato.
- Supraorbital horn core straight in lateral view, which is shared with 
Centrosaurus and Utahceratops.

Note it also has a unique combination of characters, so it not a nomen dubium.  
It differs least from Utahceratops (except for the long brow horns) and 
Anchiceratops and Arrhinoceratops (except for the straight, not recurved, brow 
horns).

The codings for Ceratops are-
?????????? ?????????? ?????????? ?1??111112 ?????????? ?????????? ?????????? 
?????????? ?????????? ?????????? ?????????? ?????????? ?????????? ?????????? 
????????

Mickey Mortimer