sulfur-oxidizing bacteria Archives

Intertwined filaments, as seen in the photo, help corroborate the conclusion that these are not marks left by animals (photo: Bruno Becker-Kerber/Harvard University)

Away Teams & Field Reports, Biosignatures & Paleobiology, Fossils & Paleontology, Microbiology & Virology, Origin & Evolution of Life, Press Release, Sample Return

Microfossils interpreted as animal traces were actually algae and bactéria

by Keith CowingMay 25, 2026May 25, 2026

A reexamination of microfossils found in the Brazilian state of Mato Grosso do Sul shows that the marks previously interpreted as traces of worms or other small oceanic animals are […]

Key features of natural mats and experimental products. (a) Reflected light micrograph of pyritized filamentous structures of unknown origin in modern hydrothermal sulfide deposits (East Pacific Rise, RV Sonne research cruise SO62, 1989). (b) Field photo of the SOB-rich spring in Bad Alvaneu, Switzerland. (c–d) Transmitted light (c) and SEM micrographs (d) of the original SOB mats. The microbial mats are composed of bundles of ~1–2 μm wide filaments containing S⁰ inclusions (bright spherules in (c), arrows in (d)). (e) Transmitted light micrographs of the Mat-ASW experiments during 80 °C incubation. Filaments are preserved and some are encrusted with S⁰ released from cells. -- Nature

Analog Studies, Away Teams & Field Reports, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Microbiology & Virology, Sample Return, Status Report, Water/Hycean Worlds & Oceanography

Experimental Diagenesis Reveals Preservation Of Biosignatures In Filamentous Sulfur Mats Under Hydrothermal Conditions

by Keith CowingNovember 5, 2025November 5, 2025

Filamentous microbial biosignatures associated with iron sulfides are among the prime targets in early life studies, but their formation and preservation are insufficiently understood.