World’s Oldest Algae Fossil Discovered

Scientists in India have discovered a pair of 1.6 billion-year-old fossils that appear to contain red algae, which may be the oldest plant-like life discovered on Earth.

The fossils were discovered in sedimentary rocks in the Chitrakoot region of Uttar Pradesh and Madhya Pradesh. The earliest traces of life on Earth — in the form of single-celled organisms — go back some 3.5 billion years.

Until now, the oldest known red algae was 1.2 billion years old.

No DNA remains in the fossils to be analysed but the material structurally resembles red algae, embedded in fossil mats of cyanobacteria inside a 1.6 billion-year-old phosphorite, a kind of sedimentary rock.

Advanced tools — such as synchrotron-based X-ray tomographic microscopy — allowed scientists to observe regularly recurring platelets in each cell, which they believe are parts of chloroplasts, the organelles within plant cells where photosynthesis takes place.

Distinct structures at the centre of each cell wall are also apparent, and are typical of red algae.