Achelousaurus

[Jeffrey Martz <martz@holly.ColoState.EDU>]

     And here is the Achelousaurus stuff, same again.  As I understand it, 
the Rogers reference for Einiosaurus (1990, Palios 5:394-413) deals 
exclusively with and Einiosaurus bone bed and makes no mention of 
Achelousaurus.  Is this correct?

LN Jeff
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GENUS: _Achelousaurus_ (Sampson, 1995b)
Synonyms: *1

_Acehelousaurus_ _horneri_ (Sampson, 1995b)
Synonyms: *1
Etymology: Greek Achelous (mythical river god) + Greek sauros (lizard)
           "_horneri_" (for Jack Horner, paleontologist)               
Synonyms: *1
Holotype: MOR 485
Referred specimens: MOR 591, MOR 571 *2
Formation & location: Two Medicine Formation
                      Montana, United States
Taxonomy:
CERATOPSIA Marsh, 1890
CERATOPSIDAE Marsh, 1888
CENTROSAURINAE Lambe, 1915
     Sampson (1995) considers _Achelousaurs_ to be a taxon with close ties 
to _Einiosaurus_ and _Pachyrhinosaurus_, while Horner et. all 
(1992) postulate is an intermediate form between _Einiosaurus_ and 
_Pachyrhinosaurus_.

Estimated adult skull length: ~1.6 m   

Description:

     _Achelousaurus_ _horneri_ had well developed supraorbital and nasal 
bosses similar to those of _Pachyrhinosaurus_, although the nasal boss 
was slightly smaller and the supraorbital bosses weres lightly larger.  
Both may have been used for intraspecific combat.  It also 
possesed twin parietal spikes, a feature it shared with _Einiosaurus_.  
Achelousaurus was an average sized centrosaur for its time, although 
apparently somewhat more robust than _Einiosaurus_.    

*1: Any at all?
*2: Any additional specimens?

PUBLICATIONS
Horner, J.R., Varricchio, D.J., Goodwin, M.B. 1992. Marine transgressions 
   and the evolution of Cretaceous dinosaurs. Nature 358:59-61.
Sampson, S.D. 1995a. Horns, herds, and heiarchies. Natural History 
   104(6):36-40.
Sampson, S.D. 1995b. Two new horned dinosaurs from the Upper Cretaceous Two 
   Medicine Formation of Montana; with a phylogenetic analysis of the 
   Centrosaurinae (Ornithischia: Ceratopsidae). Journal of Vertebrate 
   Paleontology 15(4):743-760.