What’s probably the most spectacular fossil you ever noticed? For most individuals — those that aren’t paleontologists — the reply would in all probability veer in direction of the A-list of historic creatures: dinosaurs, pterosaurs and different long-extinct megafauna whose measurement and majesty have made them the showpieces of museums and the inspiration of movie franchises for many years.
However what if somebody advised you that you simply’ve been overlooking the actual rock stars of the fossil document for all these years? What if there was a kind of creature that was a lot, a lot older than the dinosaurs, whose presence on Earth actually modified the way forward for the planet? And what should you knew that someplace on the planet, dwelling examples of this historic life type nonetheless exist — and you possibly can go to them should you needed to?
Now that’s spectacular. And that’s what you get with stromatolites.
Stromatolite Fossils
Stromatolites weren’t one distinct creature, however many — they’re fashioned by colonies of cyanobacteria, microscopic organisms that use photosynthesis to maintain themselves. Dwelling principally in water, the colonies that made stromatolites have been considerably sticky, because of a compound they secreted, which triggered sediment to construct up across the cyanobacteria.
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Over time, stromatolites would accumulate a number of layers of sediment (stromatolite comes from the Greek phrases that actually imply layered rock), though they might type in numerous shapes – some flat, some spherical, some mushroom-shaped or mound-like. However they did extra than simply present sticky locations for dust and rock to settle. Listed below are a couple of details value figuring out about stromatolites:
Cyanobacteria Stromatolites As soon as Dominated the Planet
Lengthy earlier than any form of creatures walked the Earth, in a time that predates even the existence of marine or plants, stromatolites have been already right here. Billions of years in the past, our younger planet, as soon as too scorching and its floor too molten to harbor life, had begun to chill. This allowed the primary oceans to type.
Earth was nonetheless not a hospitable place, however easy micro organism may survive and type colonies that may develop into stromatolites. For a minimum of two billion years, these sticky little cyanobacteria stromatolites have been the dominant life type on Earth.
When Did Stromatolites Seem on Earth?
Historical Stromatolite Fossils (Credit score: Peter Olsson/Shutterstock)
Stromatolites predate the dinosaurs by a large margin. Not solely have been they as soon as the first type of life right here, as micro organism they’re additionally the oldest recognized life on Earth and are discovered within the oldest fossils ever found. Proof of their existence stretches again as a lot as 3.5 billion years, to an nearly unimaginably distant time referred to as the Archean Eon.
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Again then, Earth was nothing like it’s now. Have been you to go to it throughout Archean instances, you wouldn’t final lengthy: The environment of the planet then was a mixture of gasses like carbon dioxide, methane and ammonia, amongst others, that may have been poisonous to Earth’s present inhabitants. However that wasn’t the case for stromatolites, after all. They thrived on this setting, at the same time as they have been slowly altering it.
Why Are Stromatolites Vital?
Dwelling stromatolites, as seen from the overlook at Hamelin Pool Nature Reserve, Australia. (Credit score: Benny Marty/Shutterstock)
In actual fact, most of life as we all know it will by no means have developed on earth with out these tireless little cyanobacteria colonies. Due to the wonders of photosynthesis, stromatolites of their billions have been busily absorbing daylight, water and carbon dioxide whereas pumping out tiny bubbles of oxygen into the world’s oceans.
That doesn’t sound like a lot of a job, however the stromatolites of early Earth stored at it lengthy sufficient that, over the eons, the oceans grew to become saturated with oxygen. Ultimately, this crucial fuel started to be launched into the environment, creating an setting that may assist extra advanced types of life, together with the dinosaurs and, finally, us.
However lengthy earlier than that occurred, roughly one billion years in the past, stromatolites started to vanish from the fossil document. A number of theories abound, however researchers consider that modifications within the chemical composition of the world’s oceans, or maybe the rise of extra advanced life that consumed cyanobacteria, have been in all probability accountable for wiping out most stromatolites.
Most, however not all.
Are Stromatolites Alive?
Bacalar Lagoon Stromatolites in Mexico. (Credit score: Rubi Rodriguez Martinez/Shutterstock)
If somebody advised you that you possibly can hop on a airplane and go to a herd of dwelling dinosaurs, you’d go, proper? Nicely, should you’re so inclined, you’ll be able to truly see colonies of dwelling stromatolites for your self.
Up to now, scientists know of some places world wide the place stromatolites can nonetheless reside — usually, they require very salty and sheltered water environments. Probably the most well-known locations — well-known amongst stromatolite followers, anyway — is Western Australia’s Hamelin Pool Marine Nature Reserve. Australia can also be residence to a fair rarer type of cave-dwelling stromatolite.
Different dwelling stromatolites have additionally been discovered within the Bahamas and Mexico, amongst a couple of different locations. The ecosystems that stromatolites require to thrive are delicate and most of those uncommon enclaves of dwelling fossils are beneath menace.
What Do Stromatolites Look Like?
Except you’re ready to be philosophical concerning the expertise, you could be a little bit underwhelmed at your first sight of a dwelling stromatolite. They’re not visually thrilling, since they have an inclination to look loads like moist mats or weirdly formed rocks.
Seeing a bunch of reside stromatolites wouldn’t have fairly the adrenaline-inducing sense of journey that you simply would possibly really feel if it have been attainable to go to, say, a herd of stegosauruses or a pack of velociraptors. However a minimum of stromatolites gained’t attempt to trample or eat you.
As an alternative, these unassuming piles of sediment and micro organism will simply maintain doing what they’ve been doing for billions of years: pumping out extra oxygen and storing extra carbon, usually making the world a extra hospitable place for creatures like us. You’re welcome!
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