(Supplementary Material 2) Landmark coordinates of the analyzed specimens with associated metadata@en

The use of planktonic foraminifera in paleoceanographic studies relies on the assumption that morphospecies represent biological species with ecological preferences that are stable through time and space. However, genetic surveys unveiled a considerable level of diversity in most morphospecies of planktonic foraminifera. This diversity is significant for paleoceanographic applications because cryptic species were shown to display distinct ecological preferences that could potentially help refine paleoceanographic proxies. Subtle morphological differences between cryptic species of planktonic foraminifera have been reported, but so far their applicability within paleoceanographic studies remains largely unexplored. Here we show how information on genetic diversity can be transferred to paleoceanography using Globorotalia inflata as a case study. The two cryptic species of G. inflata are separated by the Brazil-Malvinas Confluence (BMC), a major oceanographic feature in the South Atlantic. Based on this observation, we developed a morphological model of cryptic species detection in core top material. The application of the cryptic species detection model to Holocene samples implies latitudinal oscillations in the position of the confluence that are largely consistent with reconstructions obtained from stable isotope data. We show that the occurrence of cryptic species in G. inflata, can be detected in the fossil record and used to trace the migration of the BMC. Since a similar degree of morphological separation as in G. inflata has been reported from other species of planktonic foraminifera, the approach presented in this study can potentially yield a wealth of new paleoceanographical proxies.古海洋学研究中应用浮游有孔虫（planktonic foraminifera）时，需依托一项核心前提假设：即形态种（morphospecies）代表着具备时空稳定生态偏好的生物种（biological species）。然而，遗传调查结果显示，多数浮游有孔虫形态种内部存在可观的遗传多样性。这种多样性对古海洋学应用具有重要意义，因为已有研究证实隐存种（cryptic species）拥有迥异的生态偏好，或可助力优化古海洋代用指标（paleoceanographic proxies）。虽有文献报道浮游有孔虫的隐存种间存在细微形态差异，但截至目前，其在古海洋学研究中的应用仍未得到充分探索。本研究以膨大拟抱球虫（Globorotalia inflata）为案例，展示了如何将遗传多样性信息应用于古海洋学研究。该物种的两个隐存种以巴西-马尔维纳斯汇流区（Brazil-Malvinas Confluence, BMC）为界，该汇流区是南大西洋的关键海洋学特征。基于这一观测结果，我们构建了适用于岩芯表层沉积物（core top material）的隐存种形态检测模型。将该模型应用于全新世（Holocene）样品的分析结果显示，汇流区的位置存在纬度波动，这与稳定同位素（stable isotope）数据重建得到的结果大体一致。本研究证实，膨大拟抱球虫的隐存种可在化石记录（fossil record）中被识别，并可用于追踪巴西-马尔维纳斯汇流区的迁移活动。鉴于已有研究报道其他浮游有孔虫物种也存在与膨大拟抱球虫类似的形态分化程度，本研究提出的方法或可催生大量全新的古海洋代用指标。