Stable carbon and oxygen isotope ratios of Miocene to Recent foraminifera from the Rio Grande Rise, South Atlantic@en

Miocene to Recent species of planktic foraminifera in the Globorotalia (Globoconella) lineage evolved entirely within the thermocline. All species are most abundant within subtropical-temperate watermasses throughout their history. The near stasis in distribution within the thermocline and the subtropical convergence suggests the major morphological changes in Globorotalia (Globoconella) may have occurred through habitat subdivision rather than by vicariant shifts into new watermasses. […]球室虫属（Globorotalia）球旋亚属（Globoconella）支系的中新世至现代浮游有孔虫（planktic foraminifera）物种，其演化全程均发生于温跃层环境之中。所有物种在其整个演化历史中，均以亚热带-温带水团内的种群丰度为最高。温跃层与亚热带辐合带内的分布近乎停滞，这表明球室虫属（Globorotalia）球旋亚属（Globoconella）的主要形态变化，或许是通过生境细分而非异域分化进入新水团的方式产生的。[…]