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Re: Triceratops



In a message dated 95-11-09 22:18:27 EST, zooamy@zoo.latrobe.edu.au (Adam
Yates) writes:

>Small taxonomic point: Triceratops and Torosaurus are members of the same 
>subfamily. The Ceratopidae was long regarded as divisible into long 
>frilled (including Torosaurus) and short frilled (Including 
>Triceratops) forms. However it turns out that Triceratops has much more 
>in common with the long frilled forms, such as a long squamosal bones and 
>large orbital horns and a short nasal horn. The short solid frill of 
>Triceratops is only superficially similar to the short but fenestrated 
>frills of other short frilled forms (Eucentrosaurus and relatives). The 
>two subfamilies are known as the Chasmosaurinae and the Centrosaurinae. 
>While on the topic of Ceratopids, I have question for G. O.. If the type 
>specimen of Monoclonius crassus is not determinate, then what is the 
>correct generic  designation for the skull named Monoclonius lowei? Is 
>it in limbo? Is a new name called for?
>  

Major nomenclatural faux pas being committed by all known dinosaurologists
except yours truly: The ICZN _mandates_ that the name of the subfamily
containing the type genus of the inclusive family must be the same as the
name of the family, with the subfamilial ending. Thus, if you divide the
family Ceratopidae into two subfamilies, the subfamily that contains the
genus _Ceratops_ MUST(!) be named Ceratopinae. _Ceratops_ is a ceratopid
genus _painfully_ close to being a _nomen dubium_, but it may be salvageable
by the recent discovery of more complete topotype material of the type
species _Ceratops montanus_ (reported at the 1995 SVP meeting). Assuming the
genus _Ceratops_ survives, it will probably turn out to be a long-skulled
form resembling (and close to the ancestry of) _Chasmosaurus_; so
Chasmosaurinae must be replaced by the name Ceratopinae.

I still haven't found an instance of _Centrosaurus_ Fitzinger, 1843 being
used as a standalone genus or as a genus preoccupying _Centrosaurus_ Lambe,
1904 BEFORE 1961 (Kuhn, 1964 [_Fossilium Catalogus_] is currently the
earliest, but he may have published this before 1961 in an earlier
installment). If such an instance doesn't turn up, then _Centrosaurus_ may be
considered available for the ceratopid (sigh of relief) and _Eucentrosaurus_
sinks as a junior synonym; and the name Centrosaurinae would be available for
the second ceratopid subfamily. I've been using Pachyrhinosaurinae (the next
available name in chronological order) for that subfamily, just in case,
however.

Yes, _Monoclonius lowei_ almost certainly represents a new genus, but so far
neither Scott Sampson, Cathy Forster, nor Peter Dodson (among the world's
experts on ceratopians) has volunteered to describe it. Most people still
have trouble swallowing Sampson and Darren Tanke's finding that _Monoclonius_
is indeterminate. Darren once told me how he showed Peter Dodson a juvenile
_Pachyrhinosaurus_ frill from his Grande Prairie bonebed and Peter without
hesitation identified it as "_Monoclonius_, of course." Case closed.