SGER: Excavation of a novel titanosaurian sauropod from the Late Cretaceous of southern Patagonia, Argentina

Drexel University, Philadelphia PA

Investigators

Abstract

Lacovara EAR-0603805 The work proposed here builds on the successes of a 2004 planning visit, funded by OISEs Americas Program, conducted between a group of U.S. and Argentinean researchers at a remote field location in southern-most Patagonia. Major joint accomplishments of the initial field season include the discovery and extraction of many dinosaur fossils, including a 2.22 meter-long titanosaurian femur, which is among the largest femora ever reported and appears to represent a new genus and species of dinosaur. To adequately describe this new species, however, a more complete specimen would have to be found. This goal was accomplished during a follow-up 2005 field season with the discovery of a second, nearly complete individual. Approximately half of the material found was excavated, jacketed, and transported to the Museo Padre Molina, in Rio Gallegos, Argentina. The remaining material was protected with winter-jackets of plaster and is awaiting excavation. The funding requested in this proposal would facilitate the extraction of the remaining half of this specimen, a probable future generic holotype, and would fund the shipment of the specimen to Philadelphia for preparation, study, and public display. Intellectual Merit - We estimate the mass of the sauropod represented by the new skeleton to be approximately 58 metric tons. This ranks this individual as the 2nd most massive known terrestrial animal, behind Argentinosaurus from northern Patagonia and nearly 60% more massive than Paralitian from Egypt, discovered by a team that included the P.I. Based on previous work, relatively diminutive taxa would be expected to dominate the latest Cretaceous sauropod assemblages of this region. Its discovery demonstrates that the conditions required to promote gigantism in sauropods from the Late Jurassic through mid-Cretaceous, persisted, at least in one region, up until the end of the time of dinosaurs. Numerous dinosaur discoveries from Late Cretaceous deposits have been reported from northern and central Patagonia. However, Cretaceous dinosaurs from other regions of South America, including the study area, remain poorly characterized. Given the lack of previous investigation and the fossiliferous nature of the outcrops in the study area, the proposed research has great potential to reveal new dinosaur taxa and other associated tetrapods from these highlatitude Gondwanan deposits. This will provide answers to an array of long-standing questions, such as: did a more or less homogeneous dinosaur assemblage occupy all of South America during the latest Cretaceous? This assumption has been implicit in a number of studies and the material collected during the proposed work will provide a test of its validity. Broader Impacts - The P.I. has secured funding for two Patagonian students to study for their Ph.D.s at Drexel University (DU). At least two other Ph.D. students will derive significant portions of their research from this project. Additionally, undergraduates from DU and Universidad Nacional de la Patagonia will join the 2006 excavation as part of a DU initiative to provide undergraduates with research experience. The provincial government of Santa Cruz, Argentina has issued an unprecedented fossil exportation permit to the P.I. Under the terms of the agreement, the material we collect will be on loan to Drexel University and will be prepared and studied at the Academy of Natural Sciences of Philadelphia. The specimens will become the subject of an Academy exhibit focusing on science as a process and will be seen by hundreds of thousands of visitors in Dinosaur Hall, providing the public with direct access to the results of this project and creating many valuable opportunities for interaction between visitors and DU students and scientists.