Evidence of gregariousness in rebbachisaurids (Dinosauria, Sauropoda, Diplodocoidea) from the Early Cretaceous of Neuquén (Rayoso Formation), Patagonia, Argentina

ABSTRACT

For the first time an association of adult and juvenile rebbachisaurid sauropods is described. The material comes from the Early Cretaceous locality of Agrio del Medio (Neuquén, Argentina). The three specimens apparently formed a single group, and their death seems to have been almost simultaneous. The two juvenile specimens are represented by axial and appendicular bones. They show a close relationship with Zapalasaurus bonapartei, which comes from a different sector of the same basin, but which is approximately the same age. The discovery at Agrio del Medio suggests that rebbachisaurid sauropods displayed gregarious behavior. The paleoenvironments in which rebbachisaurids are normally recorded implies a greater tolerance toward extremely arid environments than that shown by macronarian sauropods.

ACKNOWLEDGMENTS

This paper forms part of the project CGL2010-16447 subsidized by the Spanish Ministry of Science and Innovation, the European Regional Development Fund, the Museo Provincial de Ciencias Naturales ‘Prof. Dr. Juan Olsacher,’ the Dirección Provincial de Minería de la Provincia del Neuquén, and the Government of Aragón (‘Grupos Consolidados’). R. Glasgow translated the text into English. The comments of reviewers P. Mannion and J. Whitlock have improved the paper.

Handling editor: Paul Barrett.