Pronounced biotic and environmental change across the latest Danian warming event (LDE) at Shatsky Rise, Pacific Ocean (ODP Site 1210)

The early Paleogene is characterized by numerous hyperthermals, transient (< 200 kyr) ocean warming events, of which the Latest Danian Event (LDE, ~ 62.1 Ma) is one of the first. Although the LDE appears to be controlled by similar processes as early Eocene hyperthermals, the first open ocean benthic foraminiferal record across the LDE at Walvis Ridge revealed little faunal response. Here, we studied benthic foraminifera from the uppermost abyssal (2000-2500 m) ODP Site 1210, Shatsky Rise, Pacific Ocean, to provide a broader view of faunal response to the LDE. Late Danian oligotrophic background conditions are characterized by a Nuttallides umbonifera dominated assemblage. Yet, ~ 200 kyr before the LDE, benthic foraminiferal assemblages, with increased relative abundance of endobenthic morphotypes and benthic foraminiferal accumulation rates indicate a slightly enhanced food flux. A temperature increase ~ 40 kyr before the first carbon isotope excursion (CIE) of the LDE (= LDE1) is associated with a rise in abundance of Tappanina selmensis, suggesting episodic input of fresh phytodetritus. At the start of LDE1, and through the second CIE (= LDE2), the seafloor returned to more oligotrophic conditions. Between 220 and 430 kyr after the onset of the LDE, a second phase of episodic fresh phytodetritus input is suggested by a renewed dominance of T. selmensis. Although the patterns of faunal change during hyperthermals relate to local conditions (circulation patterns), the magnitude of faunal change is probably more related to an absolute temperature threshold.