1.75 Billion-Year-Old Cyanobacteria Fossils Unearth Oldest Known Photosynthetic Structures

Discovery extends the fossil record by 1.2 billion years, indicating oxygenic photosynthesis evolved at least 1.75 billion years ago.

Researchers have discovered 1.75 billion-year-old fossils of cyanobacteria, Navifusa majensis, in northern Australia, which contain the oldest known photosynthetic structures, thylakoids.
The discovery extends the fossil record of such internal membranes by at least 1.2 billion years, indicating that oxygenic photosynthesis evolved at least 1.75 billion years ago.
The cyanobacteria fossils were also found in the Grassy Bay Formation in Canada and the Bllc6 formation in the Democratic Republic of the Congo.
The presence of thylakoids in these ancient bacteria provides insights into the evolution of photosynthesis, a fundamental life process on Earth.
The findings could help understand the Great Oxidation Event, a point in Earth's history when oxygen production significantly increased, potentially due to the emergence of photosynthetic organisms.