Fire-prone Rhamnaceae with South African affinities in Cretaceous Myanmar amber

Area of Science:

• Paleobotany
• Evolutionary Biology
• Ecology

Background:

• Darwin's 'abominable mystery' concerns the rapid Cretaceous diversification of flowering plants.
• Early angiosperm fossils are often charcoalified fragments, hindering identification and ecological study.
• The role of fire in flowering plant evolution remains poorly understood due to limited fossil evidence.

Purpose of the Study:

• To investigate the ecological adaptations of early angiosperms.
• To provide evidence for fire's role in flowering plant evolution.
• To resolve Darwin's 'abominable mystery' using exceptionally preserved fossils.

Main Methods:

• Discovery and analysis of exceptionally preserved fossil flowers in Cretaceous amber (~99 million years ago) from Myanmar.
• Comparison of fossil floral structures with extant taxa from fire-prone ecosystems.
• Identification of fossilized plant remains, including burned material, within the amber inclusions.

Main Results:

• Discovery of two new fossil flower species, Phylica piloburmensis sp. nov. and Eophylica priscastellata gen. et sp. nov.
• One fossil species is identical to extant Phylica inflorescences; the other is a closely related sister group.
• Both fossil species exhibit traits characteristic of modern plants in fire-prone environments.

Conclusions:

• The findings provide direct evidence of fire adaptation in early angiosperms.
• This discovery sheds light on the ecological pressures driving flowering plant diversification.
• The exceptionally preserved fossils offer crucial insights into resolving the Cretaceous angiosperm radiation problem.