The 1 billion-year-old fossil of the oldest plant in the world

Scientists found fossils of the green algae that cover the sea floor, thought to be the earliest ancestors of terrestrial plants.

Fossils of Proterocladus.(Photo: Guardian).

According to research published on February 24 in the journal Nature Ecology & Evolution, the algae called Proterocladus antiquus is about the size of a grain of rice and consists of many thin branches, growing in shallow water and attaching to the sea floor thanks to the root structure. Despite its small size, Proterocladus was one of the largest organizations living a billion years ago, sharing its environment with bacteria and other microorganisms. The algae survive through photosynthesis, converting energy from sunlight into chemical energy and producing oxygen.

Qing Tang, a paleontologist at the Virginia Polytechnic Institute, the lead author of the study, and colleagues discovered the fossil of Proterocladus near Dalian City in Liaoning Province. According to them, the Earth's biosphere is highly dependent on plants for food and oxygen. The first terrestrial plant, a descendant of green algae, appeared 450 million years ago.

The evolutionary change on Earth could have happened 2 billion years ago from simple cells like bacteria to eukaryotes. The first plants are unicellular. The transition to multicellular plants such as Proterocladus paved the way for trees to cover the Earth, from ferns to sam.

Proterocladus is 200 million years older than the oldest green algae known to scientists. One of the modern relatives of this algae is the edible seaweed called sea lettuce.

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