Flowering plants (angiosperms), the most diverse group of plants comprising over 90% (approximately 350,000 species) of all living plant species, are the dominant ecological force in nearly all major global vegetation types outside boreal and montane coniferous forests. Since their emergence in the Early Cretaceous, angiosperms have driven the transformation of terrestrial ecosystems into their modern form, gradually replacing older groups like ferns and gymnosperms. However, a systematic understanding of how and when they achieved this dominance and reshaped Earth's ecosystems has remained elusive.
In a study published in Biological Reviews, researchers from Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences and their collaborators synthesized decades of evidence to provide a comprehensive framework for angiosperm evolution and its revolutionary impact on terrestrial ecosystems. They proposed that the stepwise rise of angiosperm-dominated ecosystems occurred through five distinct evolutionary stages.
The researchers integrated the plant fossil record and phylogenetic evidence to understand the origination, development, and establishment of major modern-type angiosperm dominated floras within their historical environmental context.
The study identified a crucial pattern: a consistent delay between the origination and taxonomic diversification of angiosperm lineages and their eventual achievement of ecological dominance.
They found that angiosperms experienced rapid divergence and geographic expansion from the early to the middle Cretaceous, but the ecosystem changes were gradual, not reaching a significantly transformed state until the late Cretaceous.
After the Cretaceous–Paleogene boundary event, angiosperms reshaped terrestrial ecosystems to resemble modern forms, with the emergence of tropical forests resembling modern compositions and structures.
In the Neogene, crown-group radiations formed the basis of modern terrestrial angiosperm biodiversity, and at the same time, regional floristic differentiation was established along intensifying latitudinal and vertical temperature gradients.
"The rise of angiosperms to global dominance was step-wise," said XING Yaowu. "Their path to ecological predominance was shaped by distinct geographical and climatic conditions in diverse regions. This multifaceted transition, which ultimately led to the present-day floral regionalization and hegemony of contemporary groups, profoundly altered terrestrial ecosystems in response to persistent environmental shifts."
First published: 30 May 2025
