1 March 2017
Scientists have discovered what they say could be fossils of some of the earliest living organisms on Earth.
They are represented by tiny filaments, knobs and tubes in Canadian rocks dated to be up to 4.28 billion years old.
That is a time not long after the planet's formation and hundreds of millions of years before what is currently accepted as evidence for the most ancient life yet found on Earth.
The researchers report their investigation in the journal Nature.
As with all such claims about ancient life, the study is contentious. But the team believes it can answer any doubts.