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In the present study, the sedimentary succession of the Danian/Selandian (D/S) transition exposed at Wadi El Maheer, north Eastern Desert, Egypt, has been subjected to quantitative high-resolution planktic and benthic foraminiferal analysis. The succession is here subdivided into six planktic foraminiferal biozones, documenting a case of continuous sedimentation during the D/S transition. The planktic foraminiferal biozones are: the Danian Praemurica inconstans (P1c), Praemunica uncinata (P2), Morozovella angulata (P3a) and Igorina albeari/Praemurica carinata (lower most part of P3b) biozones and the Selandian I. albeari (main part of P3b) and Globanomalina pseudomenardii (P4a) biozones. The D/S boundary is marked by a distinctive organic-rich phosphatic shale layer (similar to 25 cm thick) within the upper part of the Dakhla Formation, corresponding to the last appearance datum of P. carinata (El Naggar). The concerned organic-rich phosphatic shale layer reflects a deficiency in the marine oxygen content with bottom water rich in organic matter during its deposition. It is characterized by changes in both planktic and benthic foraminiferal fauna. Across the D/S boundary, the planktic foraminiferal taxa of the nonspinose praemuricids were gradually replaced by nonspinose morozovellids and acarininids, whereas the Danian outer neritic-upper bathyal benthic foraminiferal taxa were substituted by inner-middle neritic ones indicating shallowing at the D/S boundary. The Selandian deposits are marked by planktic and benthic foraminiferal genera of outer neritic-upper bathyal conditions. Oscillation in the mean sea level during the D/S transition was probably due to a true eustatic change rather than to a tectonic origin. (C) 2008 Elsevier Ltd. All rights reserved.