2024/06/17 by Aihua Yang, Bo Chen, Zhixin Sun +10 · 1 voice · 14 citations
Earth and Planetary Sciences · Environmental Science · #Biology #Deoxygenation #Event (particle physics) #Geological and Geophysical Studies #Geology #Methane Hydrates and Related Phenomena #Oceanography #Ordovician #Paleontology #Paleontology and Stratigraphy of Fossils #Spice #Trilobite
paper · doi:10.1130/g52200.1
published in Geology 52(9), 661-666 (Geological Society of America)
openalex publication_date 2024/06/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Abstract The spread of marine anoxia is believed to have played a key role in the development of the SPICE (Steptoean Positive Carbon Isotope Excursion) event and the end-Marjuman extinction in the late Cambrian (~497.5 m.y. ago), but their cause-and-effect relationship is poorly constrained. Here we present an integrated analysis of carbonate δ13C, cerium anomalies (Ce/Ce*), and genus-level diversity data of trilobites from the North China Platform. Our results show tightly coupled changes between the SPICE, an increase in Ce/Ce*, and a trilobite turnover event, which we interpret as indicating enhanced productivity and organic remineralization, leading to the development of low-oxygen conditions in shallow-water settings. This study therefore establishes a direct link between local ecological stress and trilobite turnover during the global SPICE event. Furthermore, the presence of low-oxygen rather than fully anoxic conditions during the peak of the SPICE event could explain the nature of the end-Marjuman crisis, which was characterized by the replacement of shallow-water fauna by deeper-water counterparts that were potentially more tolerant of hypoxia.