Abstract

Nannofossils were studied, recovered from Late Pliocene–Pleistocene sediments at station 3316 on cruise 46 of the R/V Akademik Ioffe north of the Rio Grande Rise in the Southwest Atlantic. The presence of irregular discoasters in a narrow horizon at the end of the Discoaster brouweri zone of the Upper Pliocene indicates dramatic changes in the living conditions of these organisms, which led to deviations in the regular structure of their skeletons and subsequent extinction at the end of the Pliocene.

中文翻译：

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西南大西洋沉积物中不规则的上新世末期灾害

摘要

在西南大西洋的里奥格兰德河以北的R / V Akademik Ioffe巡洋舰46的3316站，从晚上新世至更新世沉积物中回收了纳米化石，并进行了研究。在上新世上Discoaster brouweri区域的尽头，狭窄的地平线上有不规则的Discoaster，表明这些生物的生存条件发生了巨大变化，从而导致其骨骼的规则结构发生了变化，并在随后的末期灭绝。上新世。