T16 Piecing Together the Extinction Puzzle I: Integrated Approaches to Quantifying Organism-Environment Interactions

Sunday, 22 September 2024
8:00 AM - 12:00 PM
204C

CLIMATE FORCING, SPECIES TRAIT ADAPTATION, AND MARINE EXTINCTION PATTERNS OF THE PALEOCENE-EOCENE THERMAL MAXIMUM

Paper number: T16-2
Program: Technical Sessions
Time: 8:20 AM – 8:35 AM

Authors

Abstract

Paleoclimate intervals of rapid warming are potential analogues of the future but yield dramatically different prognoses for marine biodiversity. The end-Permian produced the largest mass extinction in Earth history while extinctions at the Paleocene-Eocene Thermal Maximum (PETM) barely register, except in the deep ocean, a striking difference that lacks quantitative explanation. Here we use climate simulations and an ecophysiological model that reproduces end-Permian extinction patterns and accounts for evolutionary adaptation of physiological traits to test three hypotheses for why extinctions were muted in the PETM: 1) Species traits adapted to a warm Paleocene climate, 2) Shallow tropical oxygenation, and 3) Weaker temperature rise compared to the end-Permian. Adaptation of species hypoxia traits to a warm Paleocene background climate ameliorates upper ocean extinctions across the PETM even without a recently hypothesized tropical O2 rise. By contrast, O2 loss in the abyss increases extinctions with habitat depth, reproducing observed trends in foraminifera. Despite trait adaptation and tropical oxygenation, PETM extinctions can rival end-Permian levels under a similar degree of temperature rise, highlighting the role of warming magnitude in extinction severity.

Geological Society of America Abstracts with Programs. Vol. 56, No. 5

doi: 10.1130/abs/2024AM-402300

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