佐渡島（新潟県）の下部中新統最上部下戸層から 産出した砂底および岩礁性軟体動物化石
2020 年 47 巻 p. 1-19
詳細
2020 年 47 巻 p. 1-19
A total of 58 molluscan species was collected from the uppermost Lower Miocene Orito Formation at Kougasezaki, Sado Island, Niigata Prefecture. Fifty-two species, including six rocky shore gastropods are first recorded from the formation. Megacardita osawanoensis (Tsuda), Vepricardium okamotoi Taguchi, Timoclea itoigawae (Tsuda), Turbo (Marmarostoma) ozawai (Otuka), Haliotis notoensis Masuda and Littorinopsis miodelicatula Oyama are briefly described. These species suggest that the formation at Kougasezaki was deposited in the intertidal zone to 10–20 m depth, associated with a rocky shore environment.
