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RE: Ugrunaaluk, new hadrosaurid from Late Cretaceous Arctic of Alaska (free pdf)



Mori et al.'s cladogram in figure 11 has the subfamily containing Saurolophus 
called Saurolophinae, but that's only true if Hadrosaurus is more basal as in 
Prieto-Marquez's work.  Since Hadrosaurus is in the 'Saurolophinae' in figure 
11, the subfamily should be called Hadrosaurinae.  Perhaps worse, in figure 12, 
Hadrosaurus is shown as the sister group to Hadrosauridae.  Impossible of 
course, and one of numerous examples of why eponymous genera should be used as 
internal specifiers.  

If we take the earliest phylogenetic definition of Hadrosauridae, from Forster 
1997 ("Lambeosaurinae plus Hadrosaurinae and their most recent common 
ancestor"), just use eponyms and make it (Lambeosaurus lambei + Hadrosaurus 
foulkii).  Then Lambeosaurinae can be (Lambeosaurus lambei <- Hadrosaurus 
foulkii), Hadrosaurinae is (Hadrosaurus foulkii <- Lambeosaurus lambei), and 
Saurolophinae is (Saurolophus osborni <- Lambeosaurus lambei).  Simple, and no 
need for any extraneous Parasaurolophus nonsense.

Mickey Mortimer

----------------------------------------
> Date: Tue, 22 Sep 2015 08:06:46 -0700
> From: bcreisler@gmail.com
> To: dinosaur@usc.edu
> Subject: Ugrunaaluk, new hadrosaurid from Late Cretaceous Arctic of Alaska 
> (free pdf)
>
> Ben Creisler
> bcreisler@gmail.com
>
> A new paper:
>
> Hirotsugu Mori, Patrick S. Druckenmiller, and Gregory M. Erickson (2015)
> A new Arctic hadrosaurid from the Prince Creek Formation (lower
> Maastrichtian) of northern Alaska
> Acta Palaeontologica Polonica (in press)
> doi:http://dx.doi.org/10.4202/app.00152.2015
> http://app.pan.pl/article/item/app001522015.html
>
>
>
> The Liscomb bonebed in the Price Creek Formation of northern Alaska
> has produced thousands of individual bones of a saurolophine
> hadrosaurid similar to Edmontosaurus; however, the specific identity
> of this taxon has been unclear, in part because the vast majority of
> the remains represent immature individuals. In this study, we address
> the taxonomic status of the Alaskan material through a comparative and
> quantitati
> adult-sized specimens with particular reference to the two known
> species of Edmontosaurus, as well as a cladistic analysis using two
> different matrices for Hadrosauroidea. In the comparative
> morphological analysis, we introduce a quantitative method using
> bivariate plots to address ontogenetic variation. Our comparative
> anatomical analysis reveals that the Alaskan saurolophine possesses a
> unique suite of characters that distinguishes it from Edmontosaurus,
> including a premaxillary circumnarial ridge that projects
> posterolaterally without a premaxillary vestibular promontory, a
> shallow groove lateral to the posterodorsal premaxillary foramen, a
> relatively narrow jugal process of the postorbital lacking a
> postorbital pocket, a relatively tall maxilla, a relatively gracile
> jugal, a more strongly angled posterior margin of the anterior process
> of the jugal, wide lateral exposure of the quadratojugal, and a short
> symphyseal process of the dentary. The cladistic analyses consistently
> recover the Alaskan saurolophine as the sister taxon to Edmontosaurus
> annectens + Edmontosaurus regalis. This phylogenetic assessment is
> robust even when accounting for ontogenetically variable characters.
> Based on these results, we erect a new taxon, Ugrunaaluk kuukpikensis
> gen. et sp. nov. that contributes to growing evidence for a distinct,
> early Maastrichtian Arctic dinosaur community that existed at the
> northernmost extent of Laramidia during the Late Cretaceous.