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The Oldest Fossils Ever Found Are Almost As Old As Earth Itself

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On the coast of Quebec, scientists uncovered the oldest fossils found so far: an astonishing 4.28 billion years old. That means they were around not long after Earth itself was formed 4.54 billion years ago.

These haematite tubes from hydrothermal vent deposits in the Nuvvuagittuq Supracrustal Belt represent the oldest microfossils ever found.

A Billion Years Older Than the Second Oldest

The fossils are of microscopic bacteria, and they're the earliest evidence of life on planet Earth we've found so far. Researchers found them in quartz layers of the Nuvvuagittuq Supracrustal Belt (NSB) in Quebec, an area known for containing some of the world's oldest sedimentary rocks. Although they were discovered on dry land, they would have lived in the ocean, surviving in hydrothermal vents. Scientists came to that conclusion based on the fact that chemical signatures in the rocks point to a deep-sea origin, along with the fact that specific structures within them appear when lava encounters water.

The research—conducted by a University College, London team led by Matthew Dodd, co-funded by NASA, and published in the journal Nature—represents another step back in time from previous research, which found fossils from Australia that suggested the earliest life on Earth existed 3.42 billion years ago. That discovery, however, came with plenty of controversy, as some scientists believed the "microfossils" were actually just regular rock. As a result, Dodd's team took great pains to prove that the tubes and filaments made of hematite (rust, basically) couldn't have been made by anything other than life. They found that the structures had the same shapes as the kinds of bacteria we find near hydrothermal vents today. That's not to mention they were found near apatite and carbonate—the same minerals you find in bones and teeth.

Microfossils in jasper rock from the Nuvvuagittuq Supracrustal Belt in Québec, Canada. The red lines are hematite.
Haematitic chert—an iron-rich and silica-rich rock—that contains tubular and filamentous microfossils. The dark green volcanic rock in the top right suggests it was located near hydrothermal vents on the sea floor.

Terrestrial Life To Extraterrestrial Life

Every time we learn more about how life could have formed on our own planet, we learn about the conditions that could make life possible on other planets. "These discoveries demonstrate life developed on Earth at a time when Mars and Earth had liquid water at their surfaces, posing exciting questions for extra-terrestrial life," Dodd said in a press release. Since scientists believe that water may have covered half of the Martian surface 4.3 billion years ago, this new evidence for life on Earth suggests that we may likely find evidence for life on Mars that far back in its history. "...if not," Dodd says, "Earth may have been a special exception."

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Key Facts In This Video

  1. About 4 billion years ago, there was no life on Earth. 00:04

  2. Without a cellular membrane to contain them, the molecules that make up enzymes and DNA would drift apart. 00:42

  3. The earliest cells were comprised of molecules that reacted with one another, sometimes producing beneficial materials for the cell membrane. 01:05

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