Recent epifaunal benthic foraminifera species of surface sediment samples along the Southeast Pacific margin@en

This study developed a unified taxonomic classification system for recent epifaunal benthic foraminifera species collected from surface sediment samples along the Southeast Pacific margin, including Cibicidoides wuellerstorfi, C. lobatulus, C. cf. ungerianus, Planulina ariminensis, P. ornata, and P. limbata. Morphological characteristics of these epifaunal benthic foraminifera specimens, such as test shape, periphery, chamber inflation, elongation, suture curvature, and wall porosity, were measured between December 2022 and June 2023. Furthermore, variations in morphological features like planoconvex tests, proloculus size, suture curvature, and pore patterns were observed among these foraminifera. The surface sediment samples were collected off the coasts of Chile and Peru between 1962 and 2014, covering latitudes from 12.70°S to 44.09°S and water depths ranging from 24 to 3,267 m. The temporal coverage of the samples spans the Holocene, with a focus on the late Holocene and modern samples. These samples were collected using various gear devices, including a multicorer (Sonne 156, Sonne 211, Meteor 92), a box corer (BIAC072014), a Petersen grab (USNS Eltanin), and a gravity core (Sonne 161). Detailed morphological examinations of the specimens were conducted using TM4000Plus HITACHI SEM imaging and a Leica S8 APO stereomicroscope, complemented by manual illustrations. The unified taxonomic criteria will enhance the accuracy of foraminifera-based proxies, such as stable isotopes and morphological studies, which are vital for paleoceanographic reconstructions.本研究针对东南太平洋边缘表层沉积物样品中采集的现生表生底栖有孔虫（epifaunal benthic foraminifera）物种，建立了一套统一的分类鉴定体系，涵盖物种包括希氏圆辐虫（Cibicidoides wuellerstorfi）、卷边圆辐虫（C. lobatulus）、相似翁氏圆辐虫（C. cf. ungerianus）、阿里米诺扁盘虫（Planulina ariminensis）、装饰扁盘虫（P. ornata）以及缘边扁盘虫（P. limbata）。2022年12月至2023年6月期间，研究人员对这批标本的形态特征开展了测量，指标涵盖壳体形态、壳缘、房室膨胀程度、延伸度、缝合线曲率及壳壁孔隙度等。此外，研究还观测到该类有孔虫在平凸壳体、初房大小、缝合线曲率以及孔隙样式等形态特征上存在种间差异。本研究所用表层沉积物样品于1962年至2014年间采自智利与秘鲁近岸海域，采样纬度范围为12.70°S至44.09°S，水深区间为24 m至3267 m。样品的时间跨度覆盖全新世，研究重点聚焦于晚全新世与现代样品。这批样品通过多种采样装置获取，包括多管取样器（Sonne 156、Sonne 211、Meteor 92）、箱式取样器（BIAC072014）、彼得生采泥器（USNS Eltanin）以及重力柱状取样器（Sonne 161）。标本的详细形态检测采用TM4000Plus日立扫描电子显微镜（SEM）与徕卡S8 APO体视显微镜完成，并辅以手工绘图进行补充。这套统一的分类鉴定标准将提升基于有孔虫的代用指标（如稳定同位素与形态学研究）的准确性，而此类指标对于古海洋重建工作至关重要。