Life forms that produced oxygen appeared on Earth at least 60 million years earlier than previously thought, according to a study by scientists at Trinity College Dublin.
The organisms were responsible for adding oxygen to our atmosphere, laying the building blocks for the evolution of more complex life forms.
It was previously thought that such oxygen emitting organisms only became present here around three billion years ago.
However, while studying the patterns of chemical weathering, preserved in ancient soil found in India, geologists at Trinity College discovered that oxygen had been present at the time at elevated levels.
Such quantities of oxygen could only have been produced by organisms that convert light and carbon dioxide to water and oxygen through photosynthesis.
By using complex dating techniques they were able to determine that the soil was formed in the presence of the gas around 3.02 billion years ago, 60 million years earlier than previously thought.
The research, published in the journal Geology, is important because the spread of oxygen producing organisms was vitally important to the evolution of multi-cellular life on the planet.
The study shows that the evolutionary process began earlier than previously thought, after a short lived pulse of atmospheric oxygenation.