Re: PACHYRHINOSAUR LINEAGE

["Nicholas J. Pharris" <pharrinj@PLU.edu>]

On Tue, 5 Mar 1996, Jeffrey Martz wrote:

>      So: Achelousaurus is tied to Pachyrhinosaurus by the bosses, and 
> Einiosaurus is tied to Achelousaurus by the fact that both genera only have 
> two 
> spikes on the frill.  Also, the supraorbital horncores in all three genera 
> are apparently lost otongenetically (the younger animals have them but loose
> them as they grow older).  

Right.  _Pachyrhinosaurus_ also shows the two frill-spikes, but they are 
rotated so that the tips point outwards.  As I recall, _Achelousaurus_ 
shows bosses over the eyes as well as on the nose.

> LN Jeff

Nick Pharris
Pacific Lutheran University
Tacoma, WA 98447
(206)535-8206
PharriNJ@PLU.edu