Project Details
Projekt
Impact of hyperthermal events on deep-sea echinoid evolution immediately before the Cretaceous-Paleogene mass extinction and during their recovery phase until 61 Ma
Applicant
Privatdozent Dr. Frank Wiese
Subject Area
Geology
Oceanography
Oceanography
Term
since 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 546695930
The deep-sea is the Earth’s largest ecosystem, and due to its sheer size and inaccessibility, our knowledge on global deep-sea biota and its controlling mechanisms is still limited. Due to the scarce geologic record of deep-sea sediments onshore and the lack of continuous geological/palaeontological records of any group of higher deep-sea Metazoa, our knowledge on deep-sea palaeobiogeography and macrofauna evolution is even more rudimentary. However, an investigation of 1,400 sediment samples from ODP/DSDP/IODP core samples yielded more than 41,000 fragment of spines from Atelostomata (irregular echinoids, Holasteroida, Spatangoida), proving a continuous occurrence of the group in the deep-sea since 104 Ma and making echinoid spines the only tool to access the response of deep-sea macrobenthos to global change at a high stratigraphic resolution. Only the Cretaceous-Paleogene (K-Pg) Boundary Event with its mass extinction marks a significant break by the loss of spine size and disparity among deep-sea echinoids. The K-Pg Boundary Event is, on the other hand, sandwiched by puls-like warming phases (hyperthermal events) immediately before the impact event and after the extinction horizon during the recovery phase of the deep-sea echinoids. Because current studies on global warming show impressively that rising bottom-water temperatures in the deep-sea effect macrobenthos negatively, it is assumed that this could also have happened in the context of hyperthermal events before and after the mass extinction. Preliminary data from the North Atlantic near Newfoundland show a catastrophic drop of deep-sea echinoid biomass during a warming pulse, the Latest Maastrichtian Warming Event, with a bottom-water temperature rise of 1.8°C only 100 ky prior to the K/Pg boundary. Whether or not the echinoid fauna recovered completely before the impact or whether the first event amplified the second is tested here (Working Hypothesis 1: “The Latest Maastrichtian Warming Event had the potential to disturb the deep-sea echinoid fauna severely, and no full recovery within 100 ky until the K-Pg boundary occurred”). The post-extinction recovery of deep-sea echinoids until 61 Ma passed three hyperthermal events (Dan-C2, Latest Danian, Danian-Selandian events), which could have modulated the recovery phase (Working Hypothesis 2: “Due to high oxygen demands and complex metabolisms of echinoids, changes in echinoid mass accumulation rates, spine size and disparity represent a sensitive proxy to monitor the interaction of post-extinction recovery and hyperthermal events in the deep-sea”). Finally it is tested, whether or not the age of total deep-sea echinoid fauna recovery as suggested in the literature at 61 Ma can be confirmed (Working Hypothesis 3: The recovery of spine size and morphological inventory to pre-impact condition dates the final recovery of deep-sea echinoids from the K-Pg Boundary extinction”).
DFG Programme
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