Paleoenvironmental Recovery After the Cretaceous/ Paleogene Boundary Crisis: Evidence From the Marine

vides detailed data on the paleobathymetry as well as pa-leoenvironmental conditions across the Cretaceous/Paleo-gene (K/Pg) boundary. A quantitative analysis of benthic foraminiferal assemblages from the Upper Maastrichtian Abathomphalus mayaroensis Biozone and the Danian Guembelitria cretacea, Parvularugoglobigerina eugubina, and Parasubbotina pseudobulloides Biozones was per-formed. Benthic foraminifera indicate that the upper Maas-trichtian and lower Danian sediments at Bidart were de-posited in the upper–middle part of the slope. Benthic foraminiferal assemblages indicate mesotrophic conditions during the late Maastrichtian and a strong de-crease in the food supply to the sea floor coincident with the K/Pg boundary. This change in the trophic regime was re-lated to the collapse of the food web triggered by the mass extinction of calcareous primary producers. Benthic assem-blages in the lower Danian are strongly dominated by few species, and suggest that primary productivity was domi-nated by blooms of non-calcareous primary producers, cre-ating a stressful environment for the benthic fauna. The faunal turnover, together with the geochemical evidence, is compatible with an asteroid impact scenario. Benthic fora-miniferal assemblages suggest that primary productivity had not completely recovered more than 200 kyr after the K/Pg boundary event