NEW THEROPOD FAUNA FROM THE UPPER CRETACEOUS (HUINCUL FORMATION) OF NORTHWESTERN PATAGONIA, ARGENTINA

MOTTA, MATÍAS; ARANCIAGA, MAURO; ROZADILLA, SEBASTIÁN; AGNOLIN, FEDERICO

New Mexico Museum of Natural History Bulletin

New Mexico

Año: 2016

The present contribution describes theropod remains coming from the Huincul Formation (NeuquénGroup; Cenomanian-Turonian; Upper Cretaceous) at a single locality located in northwestern Río Negroprovince, Patagonia, Argentina. This theropod association is composed of abelisauroids, two different-sizedcarcharodontosaurid allosauroids, a coelurosaur of uncertain relationships, a megaraptoran tyrannosauroid, and apossible unenlagiid paravian. Two new theropod genera and species are here described. The new carcharodontosauridis based on an isolated postorbital bone bearing a unique prominence above the orbital brow. The new megaraptoranof uncertain affinities is described on the basis of a partially articulated tail and sacral vertebra. A new taxon ischaracterized by having notably elongate and highly pneumatic sacral and caudal vertebrae. It shows a largenumber of similarities with the African taxa Deltadromeus and Baharisaurus. These genera probably constitutea still poorly known clade of megaraptoran tyrannosauroids different from the Megaraptoridae. These findingssupport that Patagonia is a key place for understanding theropod evolution in Gondwana.