*Naoki Takahashi1, Takuya Akashi2 (1.Natural History Museum and Institute, Chiba, 2.Hisui-no-kai)
convener:Hisashi Suzuki(Otani University), Tohru Sakiyama(Institute of Geo History, Japan Geochronology Network), Naoki Takahashi(Natural History Museum and Institute, Chiba)