Dr. Jon Wilson
Haverford College

Topic: Plants: the next paleobiological revolution

Academic Hosts: Dr. Katie Snell and Dr. Lizzy Trower

Abstract: Over the last six decades, paleobiologists have transformed our understanding of invertebrate and vertebrate biodiversity and how these extinct organisms functioned, from marine ecosystem engineers to feathered dinosaurs. Today, new approaches integrating mathematical models and ecophysiological insights are transforming our understanding of how the terrestrialization of photosynthesis has shaped and responded to Earth system processes, including in deep time. Plants are unique among multicellular organisms because much of their physiology is biophysical, rather than behavioral, and the anatomy that defines these biophysical capabilities is preserved in the fossil record and can, therefore, be read from fossilized material. However, many extinct plants lack close living relatives or morphological analogues for fossilized anatomical features, limiting the ability of experimental methods to provide a perspective on extinct plant growth, development, and function. Mathematical models, when applied to fossilized plant organs—particularly leaves and stems—can provide quantitative insight into the physiology and ecology of plants that have been extinct for hundreds of millions of years.

Within the Euramerican Carboniferous tropical forests, key plants from seed and non-seed plant lineages occupied physiological niches that were later explored by flowering plants, suggesting an early history of complex physiological behavior and environmental response. Furthermore, recent work modeling extinct plants as "whole plants" allows novel insight into paleoenvironmental history, from past concentrations of carbon dioxide in the atmosphere to the breakdown of Carboniferous rainforest communities. Investigating the rich record of plant anatomy in the fossil record sheds light on ecophysiological trajectories in plant evolutionary history and is transforming our understanding of how terrestrial ecosystems responded to, and shaped, the Earth over the last 400 million years.