The timescale of early land plant evolution

TLDR

Establishing the timescale of early land plant evolution is essential to testing hypotheses on the coevolution of land plants and Earth’s System. The study integrates competing hypotheses on bryophyte–tracheophyte relationships to establish a comprehensive timescale for early land plant evolution. We estimate land plants emerged in the middle Cambrian–Early Ordovician, vascular plants in the Late Ordovician–Silurian, implying early terrestrial ecosystems and necessitating biogeochemical models to account for a much earlier origin.

Abstract

Significance Establishing the timescale of early land plant evolution is essential to testing hypotheses on the coevolution of land plants and Earth’s System. Here, we establish a timescale for early land plant evolution that integrates over competing hypotheses on bryophyte−tracheophyte relationships. We estimate land plants to have emerged in a middle Cambrian–Early Ordovocian interval, and vascular plants to have emerged in the Late Ordovician−Silurian. This timescale implies an early establishment of terrestrial ecosystems by land plants that is in close accord with recent estimates for the origin of terrestrial animal lineages. Biogeochemical models that are constrained by the fossil record of early land plants, or attempt to explain their impact, must consider a much earlier, middle Cambrian–Early Ordovician, origin.