Image description: Isaiah standing in front of a sandstone and conglomerate outcrop in the Appalachian Mountains in eastern Kentucky, USA. Isaiah is a white man with brown hair, and is wearing a tan shirt and blue hat. Behind the outcrop are green trees and a blue sky.
Isaiah Smith
Germany
September 29, 2026
Microplankton extinction and community shifts throughout the Cenozoic
The marine microplankton fossil record provides a highly spatially- and temporally- resolved archive of how life in the oceans changed over the course of the Cenozoic. Although small, microplankton form the base of marine food webs on which larger ocean life depends, and relatively small shifts in ocean temperature can cause measurable changes in assemblage composition. By studying the sedimentary record of marine microplankton, we can better understand how large-scale climatic events impacted these species, and the communities which they compose, over the last 66 million years. Spanning a range of both temporal and spatial scales, our analyses focus particularly on community composition, speciation, and extinction of planktonic foraminifera, diatoms, radiolarians, and coccolithophores. We link these macroecological patterns to species-specific traits relating to life mode and nutrient requirements, clarifying how ecological factors influence species emergence and loss over geologic timescales. We find that trophic mode—whether a species is primarily autotrophic, heterotrophic, or mixotrophic—is a key predictor of group-level extinction rate. Additionally, shifts in microplankton range and community composition are analyzed with respect to ocean temperature to explore how global microplankton biodiversity might reorganize in light of a changing climate. This information can be integrated with modern data to help assess extinction risk of extant groups and inform modern conservation planning.
Coming soon!
Image description: TBD
Christina Cespo
Mexico
October 06, 2026
paleoceanography, seaweed
TBD
