Sprecher
Beschreibung
Microorganisms have been key components of terrestrial ecosystems for over 400 million years, performing roles similar to those they fulfill in modern environments. Despite their frequently excellent preservation in ancient fossil deposits, microorganisms are challenging to document due to their small size and the limitations of brightfield microscopy. Fluorescence-based imaging techniques offer new ways to overcome these limitations by improving image quality, enabling three-dimensional modelling of microscopic structures, and distinguishing different organic materials.
We applied these methods to cherts – silica-rich sedimentary rocks – formed in environments dating from 400 to 300 million years ago. Key deposits include the Rhynie cherts (Scotland), the Massif central cherts (France), and coal balls – carbonate mineral precipitates that formed in the original peat before it underwent coalification – from the UK. These deposits all offer a record of some of the earliest interactions between plants and microorganisms and reveal how they adapted to the changing face of terrestrial habitats.
Confocal Scanning Laser Microscopy (CSLM) reveals detailed structures through high-resolution optical sectioning, while Fluorescence Lifetime Imaging (FLIM) differentiates structures based on fluorescence decay linked to chemical composition. These combined methods allow microorganisms to be studied with greater precision and help clarify the biological affinities of ancient microorganisms and the nature of their associations with plants.