Thanks to the late Coleman Burke (New York) for his encouragement and financial assistance to carry on first field explorations to La Anita farm. Dr. Yoshihiro Hayashi, former Director General, National Museum of Nature & Science, Japan, for his support for the project by funding a major part of the expedition from the internal grant from the museum. Facundo Echeverría and his wife Daphne Fraser (La Anita farm) offered their valuable geographic knowledge of these territories, allowing us an easy access to fossil sites with our 4x4 vehicles. Special thanks to Federico Braun for allowing access to his property. Oscar Canto and Carla Almazán (Secretaría de Cultura) for supporting our projects and explorations in Santa Cruz. Also, we thank the family De Pasqua for allowing the preparation of the specimen in his house during quarantine, especially to Julieta De Pasqua who assisted during the preparation of the specimen. Thanks to Santiago Miner for scanning the original bones and for designing some figures of the manuscript. Thanks are offered to Agustin Ozan for the reconstruction of this new species. Special thanks to the geologists F. Nullo, F. Varela, D. Moyano Paz, M. Coronel and E. Vera for their valuable comments on the stratigraphy and regional geology of the Chorrillo Formation. Finally, thanks to S. Rozadilla, F. Brissón Eglí, G. Muñoz, M. Cerroni and members of the LACEV team for their help during the excavation and technical preparation of the specimen. Reviews provided by Rafael Delcourt and Stephen Poropat highly improved the quality of the present paper.
A.M.A.R., M.J.M. excavated the fossil. A.M.A.R. prepared the materials. A.M.A.R., M.J.M., F.L.A. wrote the manuscript, drew the figure and conducted the phylogenetic analyses. M.M., and T.T. found the expedition and revised the manuscript. F.N. conducted the expedition and revised the manuscript.
We thank members of the 1996 expedition for discovery of the material, Q. Cao and R. Masek for fossil preparation, E. Fitzgerald and T. Keillor for molding and casting, C. Straus for CT-scanning of fossil bones, and C. Abraczinskas for specimen drawings and executing final drafts of reconstructions. We thank B. Britt for comments on an earlier version of this paper. We are indebted to the Museo de Ciencias Naturales y Antropológicas (J. C. Moyano) de Mendoza (Argentina) for permission to conduct fieldwork and to the Field Museum of Natural History for loan of avian skeletal material. 1e1e36bf2d