1. CONICET; Museo Paleontológico Egidio Feruglio; Avenida Fontana 140 Trelew 9100 Chubut Argentina
2. Bayerische Staatssammlung für Paläontologie und Geologie and Department of Earth and Environmental Sciences; LMU München; Richard-Wagner-Street 10 80333 Munich Germany
3. CONICET, IDEAN, Departamento de Ciencias Geológicas; Universidad de Buenos Aires, Ciudad Universitaria Pab. II; Ciudad Autónoma de Buenos Aires C1428EHA Argentina
4. Key Laboratory of Evolutionary Systematics of Vertebrates; Institute of Vertebrate Paleontology and Paleoanthropology; Chinese Academy of Science; 142 Xiwai Street Beijing China
5. Department of Biological Sciences; George Washington University; Washington DC 20052 U.S.A.