Dientes de carcarodontosáuridos asociados a huesos de titanosaurios en el Cretácico Inferior (Albiano) del Grupo Chubut, Provincia de Chubut, Patagonia, Argentina

JUAN IGNACIO CANALE; JOSE CARBALLIDO; ALEJANDRO OTERO; ALBERTO GARRIDO; JOSE CANUDO

El Chocón

Jornada; 28 Jornadas Argentinas de Paleontología de Vertebrados; 2014

The finding of theropod teeth between sauropod bones and carcasses was often documented, but usually without unequivocal information of prey preferences by predators, because the lack of accurate taxonomic determination. This study reports the finding of 20 theropod teeth in at least two different giant Titanosaur titanosaur sauropod disarticulated carcasses, all in the same locality, placed at Cerro Barcino Formation (Albian ). From the recovered material, 18 teeth can be assigned to Carcharodontosauridae, based on their big large size, slightly or not recurved crowns, strong enamel wrinkles, mesial carina terminates well beneath the cervix, sigmoid distal carinae and 2 ?chisel-like? denticles per mm. Carcharodontosaurids are already known for this unit by the species Tyrannotitan chubutensis which teeth are almost identical to those here described. The remaining two teeth are much smaller than the previously described, and can be assigned to Abelisauridae? (not recurved crown, hooked distal denticles) and Dromaeosauridae? (strongly recurved crown, absence of mesial denticles and carina, outline of basal cross-section 8-shaped) respectively. Morover, Tthe carcharodontosaurid teeth present the following peculiarities: about 90% of them belongs to the rostral sector of the skull (suggested by the asymmetry of the crown, given by the displacement of the carinae), they are broken at the base and preserve only the crown, and has wear facets at the tip of the mesial carinae. Such evidence is suggestive of some kind of predation behaviour, in which the predator All those characters suggest that the carcharodontosaurids might lost their anterior teeth by scratching meat from the titanosaur bones. Also, given the slow energy paleonvironment inferred for the locality, and the huge-sized bones (some of them surpassing widely 2 meters long) we postulate can suppose that the disarticulation of the titanosaur carcasses was done by the carcharodontosaurids while feeding on them.