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RE: a new herrerasairid from the upper triassic, Ischigualasto formation, Argentina!

> From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] 
> On Behalf Of Pedro de Luna
> At Zookeys:
> Alcober, O.A., & R.N. Martínez. 2010. A new herrerasaurid 
> (Dinosauria, Saurischia) from the Upper Triassic 
> Ischigualasto Formation of northwestern Argentina. Zookeys 63.
> [Sanjuansaurus gordilloi]
> best
> Peter Moon Ph.D.
> Brazil

Since it's at Zookeys, it is open access:



Herrerasauridae comprises a basal clade of dinosaurs best known from the Upper 
Triassic of Argentina and Brazil, which have yielded
remains of Herrerasaurus ischigualastensis and Staurikosaurus pricei, 
respectively. Systematic opinion regarding the position of
Herrerasauridae at the base of Dinosauria has varied. Here we describe a new 
herrerasaurid, Sanjuansaurus gordilloi gen. n., sp. n.,
based on a partial skeleton from Carnian-age strata of the the Upper Triassic 
Ischigualasto Formation of northwestern Argentina. The
new taxon is diagnosed by numerous features, including long, band-shaped and 
posterolaterally oriented transverse process on the
posterior cervical vertebrae; neural spines of the sixth to eighth dorsal 
vertebrae, at least, bearing acute anterior and posterior
processes; scapula and coracoid with everted lateral margins of the glenoid; 
and short pubis (63% of the femoral length).
Phylogenetic analysis placed Sanjuansaurus within a monophyletic 
Herrerasauridae, at the base of Theropoda and including
Herrerasaurus and Staurikosaurus. The presence of Sanjuansaurus at the base of 
the Ischigualasto Formation, along with other
dinosaurs such as Herrerasaurus, Eoraptor, Panphagia, and Chromogisaurus 
suggests that saurischian dinosaurs in southwestern Pangea
were already widely diversified by the late Carnian rather than increasing in 
diversity across the Carnian-Norian boundary.

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
Fax: 301-314-9661               

Faculty Director, Science & Global Change Program, College Park Scholars
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