Osaka Museum of Natural History, Japan

Two land bridge stages are inferred between the mainland of Japan and the adjacent continent during the past one million years, on the basis of the detailed stratigraphy of the Quaternary sequence in the mainland, its accurate correlation with the marine isotope stages (MIS) and with the ODP cores in Japan Sea, and the proboscidean biostratigraphy in the sequence. The two land bridge stages are placed at MIS 16 and MIS 12, which are indicated by the immigration of the proboscidean species from the continent, Stegodon orientalis and Palaeoloxodon naumanni respectively. An additional land bridge stage at MIS 36 is also suggested by the immigration of Mammuthus trogontherii.