June 21 , 2016

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

Matías J. Motta, Alexis M. Aranciaga Rolando, Sebastián Rozadilla, Federico E. Agnolín, Nicolás R. Chimento, Federico Brissón Egli, and Fernando E. Novas (2016)
New theropod fauna from the Upper Cretaceous (Huincul Formation) of northwestern Patagonia, Argentina.
In: Cretaceous Period: Biotic Diversity and Biogeography.
Bulletin of the New Mexico Museum of Natural History and Science 71: 231-253