Tectonic-driven climate change and the diversification of angiosperms

Area of Science:

• Paleoclimatology
• Paleobotany
• Evolutionary Biology

Background:

• The rapid diversification of angiosperms (flowering plants) during the Cretaceous period, known as Darwin's "abominable mystery," remains incompletely understood.
• Previous explanations for angiosperm radiation primarily focused on biotic interactions, with less emphasis on global climate change.

Observation:

• Mesozoic ecosystems were transitioning from dominance by ferns, conifers, and cycads to angiosperm-rich floras.
• Paleogeographic reconstructions show continental drift significantly altered global climate patterns throughout the Mesozoic Era.

Findings:

• Climate modeling reveals that the breakup of Pangea led to a decrease in arid desert belts and the establishment of humid conditions in the Late Cretaceous.
• This shift towards temperate, humid climates coincided with the initial rise and diversification of angiosperms.
• Fossil site locations for angiosperm-bearing flora strongly correlate with paleobioclimatic zones identified as temperate and humid.

Implications:

• Continental drift and associated climate change played a crucial role in facilitating the ecological expansion and diversification of angiosperms.
• This study highlights the importance of paleoclimatic factors in understanding major evolutionary transitions in plant life.