Oldest Complex Fossils on Earth
Millions of years before hikers and livestock roamed the Ediacara Hills, the region was home to ancient creatures that mark the birth of animal life. In 1946, geologist Reg Sprigg was exploring the mountainous region in the Flinders Ranges, South Australia, when he came across fossilised imprints of soft-bodied organisms on slabs of quartzite and sandstone. Some had disc-shaped forms like jellyfish, others bore resemblance to worms and arthropods, and others were completely foreign. Sprigg first thought these fossils were from the Cambrian period, but later work showed they were Precambrian—a new geological period was created, set immediately before the Cambrian from 635–541 million years ago, and it was named after the Ediacara Hills. “Ediacara” comes from the Indigenous phrase for “veinlike spring of water”, so it’s pretty fitting that at that time, the region was underwater. The fossils are actually of marine animals, and they existed before animals had skeletons—they represent the oldest complex organisms on Earth. Other fossils of Precambrian soft-bodied organisms had been found before, scattered all over the world, but Ediacara Hills’ collection is the most diverse and most well-preserved. Over 40 different types of organisms have been identified so far, and NASA has even funded some work in the region in the hopes it will shed light on how life might evolve on other planets.