Oldest Fossil in the World is 3.7 Billion Years Old

The oldest known fossil in the world has been found in Greenland by researchers and is believed to be 3.7 billion years ago, which is 220 million years earlier than the prior oldest known fossil found in Australia.

Science Daily reports that the fossils they found are stromatolites, which are formed by ancient microbes. The researchers discovered the stromatolites embedded in the world's oldest sedimentary rocks found in Isua Greenstone Belt. This is along the edge of Greenland's ice cap.

Physically, stromatolites look like "domes and mounds" embedded on flat rocks. These stromatolites are formed by ancient microbes that lived in large mats that created "sticky mucus," which catch sand grains and minerals. Bacteria will soon shift upwards as they continue to grow. This process will leave "layers of minerals, which will then solify to what wee see as domes and mounds today.

Professor Nutman from UOW's School of Earth and Environmental Sciences, who also led the research, said, "The significance of stromatolites is that not only do they provide obvious evidence of ancient life that is visible with the naked eye ,but that they are complex ecosystems."

Nutman also said the stromatolites they discovered reveals that even 3.7 billion years ago, there is diversity in microbial life. He also added that life was materialized during the Earth's first few hundred million years, which is aligned with the biologists calculations that reveals "the great antiquity of life's genetic code."

Due to its importance, identifying stromatolites is heavily scrutinized by experts. There are even long debates about any newly discovered stromatolites to prove that they are indeed the real deal. There is a possibility that some rocks can be similar with stromatolites yet they aren't made by ancient microbes, according to The Atlantic.

Live Science notes that the latest findings will now agree with theories that suggest that Earth appeared during the Hadean eon. This period happened more than 4 billion years ago and is believed that during this era, Earth was clobbered by icy comets and large meteorites and was also in the midst of excruciating volcanic activity. During this period, ancient bodies of water on Earth's surface were created.