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A regional unconformity at the Danian-Selandian (D/S) boundary is recorded in Western Desert, Egypt, based upon field study, biostratigraphic analyses and paleoenvironmental parameters. This unconformity is marked by the absence of the topmost part of planktonic foraminifera Igorina albeari/Globanomalina pseudomenardii (P3b) Subzone and the uppermost part of the equivalent calcareous nannofossil Ellipsolithus macelus NP4 Zone (NTp8A-B Subzones) in all the sections studied. Furthermore, benthic foraminiferal turnover across the D/S unconformity is observed to be associated with a sharp lithological break from place to place due to submerged paleo-lows and highs. In all the studied sections, intensive reworking of older Danian faunas is recorded within the basal part of Selandian transgressive deposits. (C) 2014 Elsevier Ltd. All rights reserved.