Three dimensional reconstructions of Nummulites tests reveal complex chamber shapes

Area of Science:

• Paleontology
• Micropaleontology
• Biostratigraphy

Background:

• Larger benthic foraminifera (LBF) are significant carbonate producers in tropical seas.
• The Paleogene genus Nummulites is globally distributed and crucial for biostratigraphy.
• Current Nummulites classification relies on external features and 2D sections, limiting evolutionary and biogeographical insights.

Purpose of the Study:

• To investigate the 3D chamber morphology of Nummulites djokdjokartae using micro-CT scanning.
• To compare 3D chamber shapes with traditional morphometric characters from thin sections.
• To assess the utility of 3D reconstructions for refining Nummulites classification and evolutionary studies.

Main Methods:

• Micro computed-tomographical (micro-CT) scanning to visualize internal structures.
• 3D reconstruction of Nummulites djokdjokartae tests.
• Comparative morphometric analysis of 3D chamber shapes versus traditional 2D section data.

Main Results:

• Micro-CT scanning revealed irregular 3D chamber shapes in Nummulites djokdjokartae.
• Traditional equatorial and axial thin sections do not accurately predict the complex 3D chamber morphology.
• Discrepancies highlight limitations of 2D-based classification for understanding Nummulites evolution.

Conclusions:

• 3D reconstructions offer a more accurate representation of Nummulites test morphology.
• This approach is vital for improving the classification framework of the genus Nummulites.
• Enhanced understanding of Nummulites evolutionary and biogeographical history is achievable through 3D analysis.