1. Department of Geology and Paleontology, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005, Japan (e-mail: )
2. Hobetsu Museum, 80-6, Hobetsu, Mukawa, Hokkaido 054-0211, Japan
3. N28 E21-1-3, Higashi-ku, Sapporo, Hokkaido 065-0028, Japan