An assemblage of the burrowing ghost shrimp, Protocallianassa faujasi, is described, providing the first evidence of this decapod species from Sweden. The fossils occur in successions of the informal earliest late Campanian Belemnellocamax balsvikensis zone at Åsen and the latest early Campanian B. mammillatus zone at Ivö Klack, both in the Kristianstad Basin of NE Skåne. Numerous, heavily calcified chelipeds were found within a restricted bed at Åsen that was rich in carbonate-cemented nodules. Based on the burrowing lifestyle of modern mud shrimps, we interpret these nodules as infilled burrow chambers. The low abundance of molluscs within the Protocallianassa beds is also consistent with analogous extant communities, indicating that a similar ecologically exclusive relationship ruled within the Late Cretaceous shallow-marine ecosystems.

Patterns of diversification and longevity in Paleogene coccolithophorids are analyzed by combining the temporal history of selected genera, families, and orders with the number of discrete morphospecies in them. The coccolithophorids underwent an abrupt mass extinction at the Cretaceous/Paleogene boundary, and a rapid (~1 m.y.-long) global turnover at the Paleocene/Eocene boundary. In contrast, they underwent a diachronous turnover at the Eocene/Oligocene boundary that spread over 6–7 m.y. at mid- and low-latitudes. The turnover included sequential extinctions and speciations of short-lived taxa, beginning slightly before 37 Ma, and losses of taxa that dominated mid- and low latitudes at 34.2 Ma and high latitudes at 32.3 Ma. It is also marked by a few evolutionary appearances, in particular, that of the Family Syracosphaeraceae, which is the most diversified of the living coccolithophorids. Most importantly, the turnover resulted in a shift in the balance between families across several orders, such that families that dominated during the Eocene dwindled during the turnover, and, conversely, families that were little diversified during the Eocene became dominant. Thus, members of Family Coccolithaceae and the genus Heliodiscoaster typify Eocene communities; members of the Family Calcidiscaceae and the genus Eudiscoaster characterize Neogene communities. This shift was accompanied by a decrease in the robustness of coccoliths, suggesting that the Eocene/Oligocene event had a marked effect on the physiology of Eocene coccolithophorids. Bolide impacts and the emplacement of large basaltic provinces provide mechanisms to explain large biotic events. Such mechanisms, however, can be ruled out in the case of the Eocene/Oligocene turnover, which was undoubtedly related to climatic cooling and glaciation. The filtering effect of environmental stress on late Eocene diversity remains to be explained.