In Stockholm, Sweden student Therese Sallstedt made an amazing discovery as she was looking through samples of single-celled life. The rocks that she was examining were 1.6 billion-year-old fossilized single-celled microbes that were taken from the Chitrakoot District in Central India. After going through some of the slides under her microscope, Sallstedt saw the world's oldest plant Fossil, a clump of red algae.

What exactly is this plant fossil?

The fossil is a large, fresh mass of complex life in the form of multicellular red algae lodged inside mats of cyanobacteria that are called stromatolites.

The red algae is shown in the accompanying picture with this article and is highlighted in light green. The previously oldest accepted fossil of complex life, also a red algae, is 1.2 billion years old. That means that this new fossil is around 400 million years older than the previously oldest known fossil of complex life. Unfortunately, this fossil is so old that there is no remaining DNA to study.

How does this find change scientific knowledge?

This finding could completely change the Cambrian Explosion period, which took place around 600 million years ago and was when most major animal phyla (algae, plants and fungi) are believed to have appeared on Earth. Since the red algae fossil that was found was in the rocks dates back 1.6 billion years, it could change the narrative of when complex life was first thought to have evolved on the planet by hundreds of millions of years.

It could also affect the major belief of the Cambrian Explosion period, with scientists having to analyze if it took longer to develop than previously thought.

Questions arising

This finding, together with the 1.2 billion-year-old fossil previously mentioned, now has some scientists wondering why complex life took about one billion years to really take hold on Earth after it evolved. Now scientists are asking a question that they do not have the answer to, which might lead to new theories of how early life developed.