The stepwise rise of angiosperm-dominated terrestrial ecosystems

Area of Science:

• Paleobotany
• Evolutionary Biology
• Ecology

Background:

• Angiosperms are the most diverse and abundant plant taxon, dominating Earth's terrestrial ecosystems.
• They experienced rapid divergence and expansion from the early to middle Cretaceous, with progressive ecological dominance until the Late Cretaceous.
• Post-Cretaceous-Paleogene (K-Pg) boundary, angiosperms restructured ecosystems, leading to modern forms and Neogene radiation of crown groups.

Purpose of the Study:

• To summarize the evolutionary history of angiosperms.
• To elucidate when and how angiosperms diversified, dominated, and shaped terrestrial ecosystems.
• To highlight five major phases of angiosperm evolution influenced by paleogeography and climate change.

Main Methods:

• Review of fossil evidence.
• Analysis of molecular evidence.
• Integration of paleogeographic and climate data.

Main Results:

• Angiosperm ecological dominance was a progressive process, not a single event, with a consistent delay after lineage origination and diversification.
• Five major evolutionary phases of angiosperms are identified against a backdrop of environmental changes.
• Modern angiosperm diversity, distribution, and dominance reflect contingent evolutionary processes and long-term environmental shifts.

Conclusions:

• Angiosperm ecological dominance and diversification unfolded over extended periods, influenced by environmental changes.
• Understanding angiosperm origins, diversification, and ecological dominance requires further research into their early forms, functions, habitats, and interactions.
• The patterns of extant angiosperm diversity and distribution are a result of contingent evolutionary pathways within changing environments.