Hamelin Pool Stromatolites (and friend)

           We owe our life to 3 billion year old stromatolite fossils , What is the most impressive fossil you have seen? For most people—those who aren’t paleontologists—the answer is likely to turn to the A-list of ancient creatures: dinosaurs, pterosaurs, and other long-extinct megafauna whose size and grandeur made them museum exhibits and the inspiration of film franchises for decades.

But what if someone tells you that you’ve been neglecting real fossil rock stars all these years? What if there was a species of creature that was much, much older than the dinosaurs, whose presence on Earth literally changed the future of the planet? And what if you knew that somewhere in the world living examples of this ancient life form still existed—and you could visit them if you wanted to?

Now It is impressive. And that’s what you get stromatolites.

Stromatolite fossils

Stromatolites are not one single creature, but many – they are formed by colonies of cyanobacteriamicroscopic organisms they use photosynthesis to be maintained. Living primarily in water, the colonies that create stromatolites are somewhat sticky, thanks to a compound they secrete that causes sediment to build up around the cyanobacteria.

Read more: Minerals reveal new understanding of early life on Earth

Over time, stromatolites would have accumulated multiple layers of sediment (stromatolite comes from the Greek words that literally mean layered rock), although they can have different shapes – some flat, some round, some mushroom-shaped or mound-like. But they did more than just provide sticky places for dirt and rocks to settle. Here are some facts worth knowing about stromatolites:

Cyanobacteria Stromatolites He once ruled the planet

Long before any creatures walked the Earth, in a time that predates even the existence of marine or plant life, stromatolites were already here. Billions of years ago, our young planet, once too hot and its surface too molten to support life, had begun to cool. This allowed the first oceans to form.

Earth was not yet a hospitable place, but simple bacteria could survive and form colonies that would become stromatolites. For at least two billion years, these sticky little ones cyanobacteria stromatolites were the dominant form of life on Earth.

When did stromatolites appear on Earth?

Ancient stromatolite fossils (Photo: Peter Olsson/Shutterstock)

Stromatolites predate the dinosaurs by a wide margin. Not only were they once the main form of life here, as bacteria they are also the oldest known life on Earth and are found in the oldest fossils ever discovered. Evidence of their existence stretches back as far as 3.5 billion yearsto an almost unimaginably remote time known as Archean Eon.

Read more: What are the oldest fossils in the world?

Back then, Earth was not like it is today. If you visited during Archean times, you wouldn’t last long: the planet’s atmosphere then was a mixture of gases like carbon dioxide, methane, and ammonia, among others, that would be toxic to Earth’s current inhabitants. But this was not the case with stromatolites, of course. They thrived in this environment, although they were slowly changing it.

Why are stromatolites important?

Living stromatolites as seen from the overlook at Hamelin Pool Nature Reserve, Australia. (Credit: Benny Marty/Shutterstock)

In fact, most life as we know it would never have evolved on earth without these tireless little colonies of cyanobacteria. Thanks to the wonders of photosynthesis, its billions of stromatolites busily absorbed sunlight, water and carbon dioxide while pumping out tiny bubbles of oxygen in the world’s oceans.

It doesn’t sound like much of a task, but the stromatolites of the early Earth persisted long enough for the oceans to become saturated with oxygen over the ages. After all, this critical gas began to be released in the atmosphere, creating an environment that would support more complex life forms, including dinosaurs and, eventually, us.

But long before this happened, approximately one billion years ago, stromatolites began to disappear from the fossil record. Multiple theories are abundant, but researchers believe that changes in the chemical composition of the world’s oceans, or perhaps the emergence of more complex life that consumed cyanobacteria, were likely responsible for the destruction of most stromatolites.

Most, but not all.

Are stromatolites alive?

The stromatolites of Bacalar Lagoon, Mexico. (Credit: Ruby Rodriguez Martinez/Shutterstock)

If someone told you that you could get on a plane and visit a herd of live dinosaurs, you would go, wouldn’t you? Well, if you’re so inclined, you can actually see colonies of living stromatolites for yourself.

To date, scientists know of few places in the world where stromatolites can still live – generally they require very salty and protected water environments. One of the most famous destinations – famous among stromatolite fans anyway – is Western Australia Hamelin Poole Marine Nature Reserve. Australia is also home to an even rarer form of cave dwelling stromatolite.

Other living stromatolites have also been found in The Bahamas and Mexico, among several other places. The ecosystems that stromatolites need to thrive are delicate and most of these rare enclaves of living fossils are under threat.

What do stromatolites look like?

Unless you’re prepared to wax philosophical about the experience, you might be a little disappointed at your first glimpse of a living stromatolite. They are not visually exciting as they look a lot like wet mats or oddly shaped rocks.

Looking at a bunch of live stromatolites won’t give you the adrenaline rush of adventure you’d get if you were able to visit, say, a herd of stegosaurs or a pack of velociraptors. But at least the stromatolites won’t try to trample or eat you.

Instead, these nondescript piles of sediment and bacteria will simply continue to do what they’ve done for billions of years: pump out more oxygen and storing more carbon, generally make the world a more hospitable place for beings like us. Please!

Read more: Life on Earth may have started with a dose of poison

Source link

Leave a Reply

Your email address will not be published. Required fields are marked *