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Re: Alaskan Pachyrhinosaurus is new species (new clades)

The new paper proposes 1 new name and 1 modified name:

- Pachyrhinosaurini (Sternberg, 1950; original nomenclature = 
Pachyrhinosauridae) is all taxa closer to Pachyrhinosaurus canadensis than to 
Centrosaurus apertus.
- Pachyrostra (new clade) is the Achelousaurus horneri + Pachyrhinosaurus 
canadensis clade. Pachyrostra is the same as the clade called "Pachyrhinosaurs" 
in Currie et al's 2008 paper on P. lakustai.

----- Original Message -----
From: "bh480@scn.org" <bh480@scn.org>
To: dinosaur@usc.edu
Sent: Friday, 26 August 2011 5:56 PM
Subject: Alaskan Pachyrhinosaurus is new species

From: Ben Creisler

A new online paper:

Anthony R. Fiorillo and Ronald S. Tykoski (2011)
A new species of the centrosaurine ceratopsid 
Pachyrhinosaurus from the North Slope (Prince Creek 
Formation: Maastrichtian) of Alaska.
Acta Palaeontologica Polonica (in press)

The Cretaceous rocks of the Prince Creek Formation 
contain the richest record of polar dinosaurs found 
anywhere in the world. Here we describe a new species of 
horned dinosaur, Pachyrhinosaurus perotorum that exhibits 
an apomorphic character in the frill, as well as a unique 
combination of other characters. Phylogenetic analysis of 
16 taxa of ceratopsians failed to resolve relationships 
between P. perotorum and other Pachyrhinosaurus species 
(P. canadensis and P. lakustai). P. perotorum shares 
characters with each of the previously known species that 
are not present in the other, including very large nasal 
and supraorbital bosses that are nearly in contact and 
separated only by a narrow groove as in P. canadensis, 
and a rostral comb formed by the nasals and premaxillae 
as in P. lakustai. P. perotorum is the youngest 
centrosaurine known (70-69 Ma), and the locality that 
produced the taxon, the Kikak-Tegoseak Quarry, is close 
to the highest latitude for recovery of ceratopsid