The earliest known life forms on Earth are putative fossilized microorganisms found in hydrothermal vent precipitates.[1] The earliest time that life forms first appeared on Earth is at least 3.77 billion years ago, possibly as early as 4.28 billion years,[1] or even 4.41 billion years[3][4]—not long after the oceans formed 4.5 billion years ago, and after the formation of the Earth 4.54 billion years ago.[1][2][5][6] The earliest direct evidence of life on Earth are microfossils of microorganisms permineralized in 3.465-billion-year-old Australian Apex chert rocks.[7][8]
