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.

中文翻译：

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Thalassionema bifurcum sp. 11月，来自上新世亚南极沉积物的一种新的具有重要地层学意义的硅藻

从上新世亚南极深海沉积物（DSDP Site 513 和 IODP Site U1371）中描述了一种新的硅藻物种 Thalassionema bifurcum Kato et Suto。T. bifurcum 的地层分布可能仅限于上新世早期，并显示出非常高的丰度（通常占总硅藻组合的 50%）。通过其分叉的顶端，可以很容易地将其与其他海藻属物种区分开来。考虑到地层范围短及其独特的形态特征，该分类群似乎是识别南大洋沉积物中上新世早期的有用地层标记。