Thalassionema bifurcum sp. nov., a new stratigraphically important diatom from Pliocene subantarctic sediments

Abstract

A new diatom species Thalassionema bifurcum Kato et Suto is described from Pliocene subantarctic deep-sea sediments (DSDP Site 513 and IODP Site U1371). The stratigraphic occurrence of T. bifurcum is likely to be confined to the early Pliocene and shows remarkably high abundance (often comprising 50% of the total diatom assemblage). It can be easily distinguished from other Thalassionema species by its bifurcated apices. Considering the short stratigraphic range and its unique morphological character, this taxon seems to be a useful stratigraphic marker to identify the early Pliocene in Southern Ocean sediments.

Keywords:

• Thalassionema
• fossil diatoms
• marine
• Southern Ocean
• Pliocene
• DSDP
• IODP

Acknowledgements

We appreciate the feedback offered by two anonymous reviewers. We are also deeply grateful to Prof. Richard W. Jordan (Department of Earth and Environmental Sciences, Yamagata University), who kindly made suggestions to improve our English and gave us constructive comments. This study used samples obtained by DSDP and IODP. We would like to express our gratitude to scientific party members of DSDP Leg 71 and IODP Expedition 329 as well as the captain and crew of D/V Glomar Challenger and JOIDES Resolution. We would also like to take this opportunity to thank our colleagues at the Nagoya University (Laboratory of Geobiology) for their encouragement.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Grant-in-Aid for JSPS Fellows [grant number 16J08657].