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Recent global warming has sparked a great deal of interest for similar situations in our geological past. In the early Eocene period (from ca. 56 to 52 million years ago), several of such events have been discovered. These events, called hyperthermals, can be used to estimate the consequences of fast-paced global warming on the environment: the strongest of these events caused a global warming of at least 5°C over a period of only a few thousand years, comparable to recent warming. Based on carbon isotopic records, several other events were found that occurred much sooner. One of these events occurred around 62 million years ago during the end of the Danian period. This Latest Danian Event or LDE has been detected in sediments of most of the world's oceans, which shows a relatively modest event lasting 150 to 200 thousand years. Its impact on the environment is relatively unknown however, especially regarding the benthic (seafloor-dwelling) organisms living in the deep seas. These form earth's largest and most stable ecosystem, and changes here indicate significant changes for other ecosystems around the world. In this study we examined a core drilled on the Newfoundland Ridge by the International Ocean Drilling Program, with the goal to study the quantitative changes in the benthic foraminiferal community of the deep ocean. These small single-celled organisms form calcified shells that can be preserved in the sediment, and their specific shape tells a lot about the environment of that time. Besides this, attention was paid to sedimentation and preservation. Age and sediment rate models were constructed for the event, which might show increased sedimentation rates during the event, but the resolution pre- and post-LDE are not high enough to conclude this with high certainty. Unfortunately one of several lithified horizons covers the entire onset of the event, making that part impossible to study. These horizons contain biogenic opal and are possibly related to increased productivity of siliceous micro-organisms such as radiolarians. The largest change during the LDE is a large bloom of the species Paralabamina lunata, indicating a qualitative change in the transport of food towards the ocean floor, one of the major parameters that structure the benthic community. This change might have been related to an increased seasonality or because of a food source that P. lunata had access to that was not used by other species. At the peak of the event, a sudden, short-term increase in suspension-feeding foraminifera might indicate intensified oceanic bottom currents. These changes suggest that the LDE may have caused a temporary configuration of altered circulation and food delivery to the ocean floor. Besides these two changes, the benthic community remains surprisingly undisturbed, and no permanent biotic change was recorded. This shows that the environmental response to the LDE was mostly regionally controlled.

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