These 1 billion year old algae are probably the oldest ancestors of plants.

Fossilized remains of extremely ancient algae have been discovered near the city of Dalian in Liaoning province (China). They belong to the species Proterocladus antiquus and are just over 1 billion years old, which makes them immediately 200 million years older than the previous record holder. This discovery further expands the time limits of the existence of plant life on Earth and poses new questions for scientists.

Science is certainly interested in when the first fish got to the ground, or when its descendants climbed trees to become the ancestors of humans. But even more interesting - when the trees themselves, grass and other vegetation arose. It is known that about 450 million years ago there was a "green boom", and the number of terrestrial plants increased dramatically - but what happened before that?

For example, scientists still do not know how the process of migration of protoplants from one environment to another took place. Was it a quick evolutionary leap, from the ancient ocean directly to land, or did the plants move first to freshwater reservoirs, and from there they made it to the shore? There is also a version that the algae, the remains of which were found in China, originally originated in warm fresh shallow water, from there they got into the ocean, but due to the aggressiveness of the environment they evolved into a terrestrial species.

It is difficult to study the fossils, they are only 2 mm in size, but they are located in a layer that was clearly previously the seabed. That is, half a billion years before the emergence of vegetation on land, it was already abundantly growing in the ocean. If so, the algae found may well be the oldest common ancestor of all plants on the planet.