Lythronax argestes, the Gore King of the Southwest

["Thomas R. Holtz, Jr." <tholtz@umd.edu>]

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0079420;jsessionid=94CDB9402ECD22ED123D2BB00AE487C6

The long-awaited Wahweap Fm tyrant dinosaur (and presumed 
Diabloceratops-muncher).

Loewen MA, Irmis RB, Sertich JJW, Currie PJ, Sampson SD (2013) Tyrant Dinosaur 
Evolution Tracks the Rise and Fall of Late Cretaceous
Oceans. PLoS ONE 8(11): e79420. doi:10.1371/journal.pone.0079420

Abstract
The Late Cretaceous (~95-66 million years ago) western North American landmass 
of Laramidia displayed heightened non-marine
vertebrate diversity and intracontinental regionalism relative to other latest 
Cretaceous Laurasian ecosystems. Processes generating
these patterns during this interval remain poorly understood despite their 
presumed role in the diversification of many clades.
Tyrannosauridae, a clade of large-bodied theropod dinosaurs restricted to the 
Late Cretaceous of Laramidia and Asia, represents an
ideal group for investigating Laramidian patterns of evolution. We use new 
tyrannosaurid discoveries from Utah-including a new taxon
which represents the geologically oldest member of the clade-to investigate the 
evolution and biogeography of Tyrannosauridae. These
data suggest a Laramidian origin for Tyrannosauridae, and implicate sea-level 
related controls in the isolation, diversification,
and dispersal of this and many other Late Cretaceous vertebrate clades.

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The oldest proper tyrannosaurid discovered, but closer to the 
Tarbosaurus-Tyrannosaurus clade than is Daspletosaurus.

Etymology.
Lythronax, from lythron (Greek), gore, and anax (Greek), king; and argestes 
(Greek), the Homeric wind from the southwest, in
reference to the geographic location of the specimen within North America.

Thomas R. Holtz, Jr.
Email: tholtz@umd.edu   Phone: 301-405-4084
Office: Centreville 1216                        
Senior Lecturer, Vertebrate Paleontology
Dept. of Geology, University of Maryland
http://www.geol.umd.edu/~tholtz/
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
http://www.geol.umd.edu/sgc
Fax: 301-314-9843

Mailing Address:        Thomas R. Holtz, Jr.
                        Department of Geology
                        Building 237, Room 1117
                        University of Maryland
                        College Park, MD 20742 USA