Age model tie points of ODP Sites in the central Atlantic Ocean

The transition is part of the Pliocene to Recent "attrition" of nannofossil species that resulted from changes in the distribution of trophic resources, and deep-water and surface-water current systems, likely associated with the initiation of Northern Hemisphere glaciation.

The extinctions of Sphenolithus abies and Reticulofenestra pseudoumbilicus were analysed in detail at ODP Sites 659, 662, and 926 in the equatorial and subequatorial Atlantic. These taxa show significantly different patterns of duration and timing of decline based on high-resolution abundance records and calibration with oxygen isotope stratigraphy. The initiation of abundance decline between 3.71 and 3.67 Ma and the extinction of S. abies between 3.56 and 3.52 Ma are diachronous.