REMARKS ON THE ANATOMY OF THE PELVIC GIRDLE AND HINDLIMB OF SKORPIOVENATOR BUSTINGORRYI CANALE ET AL. (THEROPODA, ABELISAURIDAE) FROM THE UPPER CRETACEOUS OF NEUQUÉN PROVINCE, ARGENTINA

CANALE JUAN IGNACIO; NOVAS, FERNANDO EMILIO

Plaza Huincul

Jornada; Reunión de Comunicaciones de la Asociación Paleontológica Argentina; 2014

Skorpiovenator bustingorryi Canale et al. (MMCh PV 48) from Huincul Formation (Cenomanian) of Neuquén Province is one of the best- represented abelisaurid theropods. In this contribution we focus on the comparative anatomical description of the hip and hindlimb of this taxon. The ilium is long, dorsoventrally low and gently concave dorsally; like in Eoabelisaurus Pol and Rauhut. The 4o trochanter of femur is a prominent structure like in Eoabelisaurus and Xenotarsosaurus Martínez et al., different from the low ridge observed in Majungasaurus (Depéret). The proximal end of the tibia is wide in the posterior condylar sector as in Carnotaurs Bonaparte and Xenotarsosaurus, different form the narrow condition seen in Majungasaurus. The fibula has a wide and well-developed medial fossa and a projected ridge for in- terosseous membrane like in most derived abelisaurids, different from the smaller and more restricted fossa and ridge of Eoabelisaurus. The ascending process of the astragalus has a subrectangular shape as in Aucasaurus Coria et al., different from the triangular shape present in Majungasaurus. The V metatarsal is moderately developed, as in the tetanuran Allosaurus Marsh, and different to the short and stout bone in Aucasaurus. A single ungueal phalange recovered, probably from the digit II, shows the ventral furrow and the strong lateromedial asymme- try seen in other abelisauroids. Although preliminary, the characters recognized shows many shared states with other South American abelisaurids, which should support the monophyly of the clade Brachyrostra. This recovered information will be useful to resolve abelisaurid relationships in future phylogenetic analysis.