What are Stromatolites

What is the oldest thing you've ever seen? The Egyptian pyramids that are 4,600 years old? A dinosaur fossil that is 230 million years old? How about a stromatolite fossil that is 3.7 billion years old? What is a stromatolite? Stromatolites are layered rock-like structures made by the activities of microbes. To see living examples of the world's most ancient ecosystem, look no further than Shark Bay in Western Australia. Why should you care about stromatolites? Well, one of the most prevalent microbes in living stromatolites are cyanobacteria. Cyanobacteria are microbes that feed off the sun using a metabolism called photosynthesis, just like plants. One of the most important characteristics of cyanobacteria is they provide much of the oxygen we breathe. Because of these cyanobacteria, stromatolites have played an important role in creating the oxygen-rich atmosphere we have today. Also, stromatolites grow towards the sun, just as plants do. When you see the insides of a stromatolite, there can be thousands of individual layers, each layer building on top of the other. So the newest, youngest layer is always on the surface, with the microbes searching for the sun. So what are we going to do if these amazing stromatolite ecosystems ever die out? It's an important question, as living stromatolites are highly susceptible to climate change and rising sea levels. Not only do these amazing ecosystems help generate the oxygen in our atmosphere, but also living stromatolites represent an important window into the ancient Earth. Studying stromatolites helps us understand how life has adapted and evolved to the ever-changing Earth. Knowing more about our past helps guide us to understand and respond to present and future environmental issues. So if you're ever in Western Australia, be sure to stop by and gaze at these magnificent ecosystems.