A new Early Cretaceous brachiosaurid (Dinosauria, Neosauropoda) from northwestern Gondwana (Villa de Leiva, Colombia)

ABSTRACT

Brachiosaurid sauropods achieved a broad distribution during the Late Jurassic, which has been considered to provide evidence of their origins during the Middle Jurassic, prior to the breakup of Pangea. In contrast to their broad geographic distribution during the Late Jurassic, formally named brachiosaurid species from the Cretaceous have so far been restricted to the Aptian–Albian of North America, which has been interpreted as a signal of differential extinction and/or a bias in the Early Cretaceous fossil record. Here we describe a new brachiosaurid titanosauriform taxon from the Early Cretaceous of Colombia, which is represented by axial elements. The material was recovered from marine sediments of the Paja Formation (Barremian), close to the locality of Villa de Leiva. The weakly laterally expanded and divided transverse processes of the anterior-most caudal vertebrae allows the recognition of a new sauropod taxon, Padillasaurus leivaensis, gen. et sp. nov. In order to test the phylogenetic relationships of the new taxon, we performed a cladistic analysis that recovered Padillasaurus as a brachiosaurid titanosauriform. This position is supported by a combination of characters, including the presence of blind fossae in anterior caudal vertebrae. Among titanosauriforms, the presence of blind fossae in anterior caudal vertebrae is an apomorphic character that is exclusive to Giraffatitan, Venenosaurus, Cedarosaurus, and Abydosaurus. Although more complete remains are needed to test more thoroughly the affinities of the new taxon, the available evidence indicates that brachiosaurids survived at lower latitudes in Gondwana until at least the Early Cretaceous.

http://zoobank.org/urn:lsid:zoobank.org:pub:652D6B2A-7A8A-4311-8725-279BF2C9E0E3

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ACKNOWLEDGMENTS

We are grateful to the Junta de Acción Comunal Vereda Monquirá, and especially to its president, J. Gonzales, for access to the specimen housed in the Museo el Fósil (Villa de Leiva) and the permission to prepare it. This collaborative research was possible after the efforts of the late Dr. Carlos Bernardo Padilla Bernal, who gathered this team and promoted the study of these fossil remains. His continuous efforts to explore, recover, and preserve paleontological heritage in Colombia are his legacy and will endure for generations to come. We thank to J. Parra and F. H. Parra from the Centro de Investigación Paleontológica (CIP), Villa de Leiva, Colombia, for the preparation of the specimen. M. D'Emic and M. Wedel made useful comments during the preparation of the manuscript. We are grateful to the reviewers S. Poropat and E. Tschopp, and the editor R. Butler, whose comments have greatly improved this paper. R. Romero helped with the illustrations of the vertebrae. This work was financed by the Agencia Nacional de Promoción Científica y Tecnológica (ANCYT, Argentina; PICT 0808; PICT 0378), the Centro de Investigaciones Paleontológicas, and Rochem Biocare Colombia SAS. This research was developed within the framework of the cooperation agreement between CONICET (Argentina) and the CIP (Colombia).

Handling editor: Richard J. Butler.

Citation for this article: Carballido, J. L., D. Pol, M. L. Parra Ruge, S. Padilla Bernal, M. E. Páramo-Fonseca, and F. Etayo-Serna. 2015. A new Early Cretaceous brachiosaurid (Dinosauria, Neosauropoda) from northwestern Gondwana (Villa de Leiva, Colombia). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.980505.