Cenozoic Environmental Changes and Their Biogeographic Impact on Marine Plankton

Core Concepts

Cenozoic environmental changes have shaped the biogeographic response and functional diversity of marine planktonic communities, with global and regional patterns of specialization and richness decoupled during major climate events.

Abstract

The article analyzes a global dataset of Cenozoic macroperforate planktonic foraminiferal occurrences (Triton) to understand the biodiversity dynamics and biogeographic response of marine plankton to environmental changes during the Cenozoic era. Key insights: Global morphological communities became less specialized prior to the richness increase after the Cretaceous–Palaeogene extinction. Ecological specialization increased during the Early Eocene Climatic Optimum, suggesting inhibitive equatorial temperatures during the Cenozoic hothouse. Increased specialization due to circulation changes across the Eocene–Oligocene transition preceded the loss of morphological diversity. Changes in morphological specialization and richness around 19 million years ago coincided with pelagic shark extinctions. The onset of changing functional group richness and specialization between hemispheres was delayed during the mid-Miocene plankton diversification. The global response of functional groups to abiotic selection pressures may depend on the background climatic state (greenhouse or icehouse) to which a group is adapted. The detailed Triton dataset provides a unique spatiotemporal view of Cenozoic pelagic macroevolution, where global biogeographic responses of functional communities and richness are decoupled during major climate events.

Stats

Cenozoic macroperforate planktonic foraminiferal occurrences were analyzed from the global Triton dataset. The Cretaceous–Palaeogene extinction event led to a richness increase in global morphological communities. Ecological specialization increased during the Early Eocene Climatic Optimum. Increased specialization due to circulation changes preceded the loss of morphological diversity across the Eocene–Oligocene transition. Changes in morphological specialization and richness occurred around 19 million years ago, coinciding with pelagic shark extinctions. The onset of changing functional group richness and specialization between hemispheres was delayed during the mid-Miocene plankton diversification.

Quotes

"global morphological communities becoming less specialized preceding the richness increase after the Cretaceous–Palaeogene extinction" "ecological specialization during the Early Eocene Climatic Optimum, suggesting inhibitive equatorial temperatures during the peak of the Cenozoic hothouse" "increased specialization due to circulation changes across the Eocene–Oligocene transition, preceding the loss of morphological diversity" "changes in morphological specialization and richness about 19 million years ago, coeval with pelagic shark extinctions" "delayed onset of changing functional group richness and specialization between hemispheres during the mid-Miocene plankton diversification"

Key Insights Distilled From

Biogeographic response of marine plankton to Cenozoic environmental changes - Nature

by Anshuman Swa... at www.nature.com 04-17-2024

https://www.nature.com/articles/s41586-024-07337-9