CARCHARODONTOSAURID TEETH ASSOCIATED WITH TITANOSAUR CARCASSES FROM THE EARLY CRETACEOUS (ALBIAN) OF THE CHUBUT GROUP, CHUBUT PROVINCE, PATAGONIA, ARGENTINA

CANALE, JUAN I.; CARBALLIDO, JOSÉ L.; OTERO, ALEJANDRO; CANUDO, JOSÉ I.; GARRIDO, ALBERTO

ZAPALA

Jornada; XXVIII Jornadas Argentinas Paleontología de Vertebrados; 2014

The finding of theropod teeth together with sauropod carcasses has been often documented, but usually with equivocal information regarding prey/predator preferences due the lack of accurate taxonomic and taphonomic determinations. This study reports the finding of 57 theropod teeth associated with at least six titanosaur disarticulated carcasses, all from the same locality of the Cerro Barcino Formation (Albian). Fifty-five teeth can be assigned to the Carcharodontosauridae, based on their large size, not recurved crowns, strong enamel wrinkles, mesial carina terminating well beneath the cervix and sigmoid distal carinae. Carcharodontosaurids are represented in this unit by Tyrannotitan chubutensis, which has almost identical teeth to those here described. The remaining two teeth can be assigned to Abelisauridae? (not recurved crown, hooked distal denticles) and Dromaeosauridae? (strongly recurved crown, absence of mesial denticles, base outline 8-shaped) respectively. Moreover, the carcharodontosaurid teeth present the following peculiarities: about 90% belong to the rostral sector of the skull (suggested by the displacement of both carinae), they are only represented by the crown, and have wear facets at the tip of the mesial carinae. Such evidence suggests some kind of predation/scavenging behaviour, in which the predator might lose 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 that part of the disarticulation of the carcasses could be done by the carcharodontosaurids while feeding on them.