Re: Triceratops and other Chasmosaurines

[Tom Holtz <tholtz@geochange.er.usgs.gov>]

>Wanted: information on Triceratops and other Chasmosaurines, especially
>genus, species, and phylogentic relationships.

Okay, last I heard...

Anchiceratops ornatus
Chasmosaurus belli
Chasmosaurus russelli
Chasmosaurus mariscalensis
Pentaceratops sternbergi
Arrhinoceratops brachyops
Torosaurus latus
Diceratops hatcheri
Triceratops horridus
Triceratops sp. 2 of Catherine Forster

Anchiceratops is the sister-taxon to all others.  The remaining
chasmosaurines split into two groups, a Chasmosaurus-Pentaceratops group,
and the rest.  Among the first, progressive ingroups are Pentaceratops, C.
mariscalensis, C. russelli, and C. belli.  Torosaurus and Arrhinoceratops
form a clade, as do the "triceratopsians".  The validity of Diceratops and
the presence of two Triceratops species is based on work of Cathy Forster,
to be published soon (I hope!).

The above is based on Dodson and Currie (1990), Forster (1990), and Forster
et al. (1993).

Dodson, P., and P.J. Currie.  1990.  Neoceratopsia.  In, Weishampel, D.B.,
P. Dodson, and H. Osmolska (eds.), The Dinosauria, Univ. of California
Press, pp. 593-618.

Forster, C.A.  1990.  Species resolution in Triceratops: a morphometric and
cladistic approach (abstract).  Journal of Vertebrate Paleontology 10
(Supplement to 3): 23A

Forster, C.A., P.C. Sereno, T.W. Evans, and T. Rowe.  1993.  A complete
skull of Chasmosaurus mariscalensis (Dinosauria: Ceratopsidae) from the
Aguja Formation (late Campanian) of West Texas.  Journal of Vertebrate
Paleontology 13: 161-170.

                                
Thomas R. Holtz, Jr.                                   
tholtz@geochange.er.usgs.gov
Vertebrate Paleontologist in Exile                  Phone:      703-648-5280
U.S. Geological Survey                                FAX:      703-648-5420
Branch of Paleontology & Stratigraphy
MS 970 National Center
Reston, VA  22092
U.S.A.