Paleogene Ficus leaves from India and their implications for fig evolution and diversification.

Area of Science:

• Paleobotany
• Plant Evolution
• Biogeography

Background:

• The genus Ficus, crucial for ecosystems and economies, has a rich fossil record but an unclear early evolutionary path.
• Understanding Ficus's past distribution and diversification is key to comprehending its evolutionary history.

Purpose of the Study:

• To describe new fossil fig foliage from the early Paleogene of India.
• To reconstruct historical fig distributions and paleodispersal routes.
• To infer paleoclimate conditions at the time of fossilization.

Main Methods:

• Fossil identification using the Nearest Living Relative (NLR) technique.
• Analysis of leaf morphology for species identification.
• Compilation and categorization of global fossil fig records.
• Comparison of paleoclimate data with modern precipitation patterns.

Main Results:

• Three new Ficus species (F. paleodicranostyla, F. paleovariegata, F. paleoauriculata) were identified from early Paleogene deposits in Rajasthan, India.
• Fossil evidence suggests Ficus was widespread in low latitudes by the early Paleogene.
• Paleoclimate data indicate higher precipitation in the region during the early Paleogene compared to present.

Conclusions:

• The described fossils contribute to a broader understanding of Ficus's past occurrences and evolutionary trajectory.
• Findings support a Eurasian origin for Ficus and emphasize the Indian subcontinent's role in early diversification.
• The study depicts a perhumid-to-humid climate in early Paleogene India, consistent with other paleoclimate evidence.