1. Centre de Recherche en Paléontologie – Paris (CR2P, UMR 7207), MNHN, CNRS, Sorbonne Université, Muséum national d'Histoire naturelle, 57 rue Cuvier, F-75231 Paris cedex 05 (France)
2. Hokkaido Research Organization, Central Fisheries Research Institute, 238 Hamanaka, Yoichi, 045-8555 Hokkaido (Japan)
3. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008 (China)