1. National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Department of Hist. Geology-Paleontology, Athens (Greece) ekosker@geol.uoa.gr
2. CR2P (CNRS, MNHN, UPMC, Sorbonne Université), Département Origines et Évolution, Muséum national d'Histoire naturelle, case postale 38, 57 rue Cuvier, F-75231 Paris cedex 05 (France)