[D] Aucasaurus garridoi [Si] [Su] [sG] [T]
Coria, Chiappe & Dingus, 2002
Cretaceous Late Campanian
Saurischia Theropoda Abelisauridae [Carnotaurini]
Upper Rio Colorado Formation, Anacleto Member, Auca Mahuevo site, Néuquen Province, Argentina
Genus - Typespecies - Skull
Aucasaurus garridoi was discovered during 1999 by Alberto Garrido and is 70% the size of the Carnotaurus sastrei holotype specimen, it is described as the most complete abelisaur skeleton ever collected. The arms are proportionately larger than those of Carnotaurus, the skull is longer and lower and has bumps instead of the horns seen in Carnotaurus. The specimen preserves impressions of soft tissue around the pelvic region. Fusion of the scapula andcoracoid, fusion of the tibia and proximal metatarsals, and the obliteration of the neurocentral sutures suggests that MCF-PVPH-236 represents an adult animal.
The specimen had been buried at the bottom of a shallow lake; because part of its skull was broken apart, the describers suggest it may have been involved in a fight and killed when another dinosaur bit or struck its head, the exact cause of death remains uncertain.
Etymology: \\\\\\\\\\\\\\\"Auca\\\\\\\\\\\\\\\" [Mahuevo, locality] and Greek sauros = \\\\\\\\\\\\\\\"lizard\\\\\\\\\\\\\\\" - (Alberto) Garrido (discoverer)\\\\\\\\\\\\\\\'s Auca (Mahuevo) lizard.
Known material/holotype: MCF-PVPH-236, allmost complete skeleton, articulated from skull to middle section of tail 913th caudal vertebrae)
Diagnosis of genus (as for the type species). \\\\\\\\\\\\\\\"Carnotaur\\\\\\\\\\\\\\\" with skull differeing from Carnotaurus sastrei in having longer, lower rostrum and external antorbital fenestra, horizontal ventral margin of latter, complete lataral exposure of maxiallarly fenestra, frontal swellings rather than horns, and sigmoidal outline of dentigerous margin of maxilla; postcranial differences from Carnotaurus sastrei including less developed coracoidal process; relatively longer forelimb, humerus with slender, crainiocaudally compressed shaft and well-developed condyles, proximal radius lacking hooked ulnar process, and chevrons having dorsally open hermal canals.