[N] 2005 Abelisaurid remains from southern Patagonia
Rubén MARTINEZ, Fernando NOVAS and Alfredo AMBROSI0, Abelisaurid remains (Theropoda, Ceratosauria) from southern Patagonia, AMEGHINIANA(Rev. Asoc. Paleontol. Argent.) - 41 (4): 577-585. Buenos Aires, 30-12-2004.
Abstract. Here we report the discovery of abelisaurid remains from the Bajo Barreal Formation (Cenomanian-Coniacian) from the northem region of Santa Cruz Province, Patagonia, Argentina. The specimen represents the southemmost record of Abelisauridae in South America. It consists of six associated vertebrae, including cervical 10, dorsal 1, an isolated dorsal centrum, and three caudals from the rniddie portion of the tail. The vertebrae closely resembe those of other derived abelisaurids (e.g., Carnotaurus sastrei Bonaparte, Alcasaurus garridoi Coria et al.). For example, the cervicals have deep pre- and postspinal cavities, hypertrophied epipophyses, and a dorsal surface of the neural arch that is c1early delirnited from the lateral surface of the diapophysis. Caudal vertebrae exhibit the characteristically fan-shaped transverse processes seen in other abelisaurids. However, some morphological distinctions are recognized when compared with Ilokœlesia, Xenotarsosaurus, Carnotaurus, AIcasaurus and Majungathollus. The list of potential synapomorphies of the vertebral column of Abelisauria and Abelisauridae is briefly reviewed. Recent phylogenetic hypotheses on Abelisauridae are discussed.