Marine Thalassiosira species from coastal Pleistocene sediments in central Kanto Plain, Japan

Nineteen species of the diatom genus Thalassiosira Cleve, including two tentatively identified and three unidentified species, are recorded from two sediment cores, drilled in Pleistocene coastal sediments of the Kanto Plain, central Japan. Concise descriptions obtained from the light and scanning electron microscopes are provided for the 19 Thalassiosira taxa recorded. This is the first study systematically investigating the taxonomy of the genus Thalassiosira and detailing the stratigraphic distribution of each taxon from Pleistocene coastal sediments of Japan. The species diversity of the genus Thalassiosira in the Japanese Pleistocene coastal environment is as high as in recent coastal waters.