SCIENTIFIC AMERICAN - Today a stretch of Canada’s remote Northwest Territories is covered in snow-covered peaks. But more than half a billion years ago this wilderness was an ancient seafloor home to the wrinkled pancakes, fleshy fronds and spiral-shaped critters that were among Earth’s earliest complex life-forms.
Researchers recently unearthed a trove of fossils that reset what we know about when these curious creatures scuttled onto the evolutionary scene. The new fossils, described today in the journal Science Advances, also suggest that the deep sea served as an environmental cradle for complex life.
Found in the MacKenzie Mountains in Canada, the new fossils provide a rare window into the Ediacaran, a geological period that precedes the Cambrian explosion of biological diversity. To reach the site, study lead author Scott Evans, a paleontologist at the American Museum of Natural History, and his colleagues embarked on a 14-hour drive and a helicopter flight.
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The fossils date back 567 million years. This “extends early animals deeper in time,” says Mary Droser, a paleontologist at the University of California, Riverside, who was not involved with the paper but is mentioned in its acknowledgments. She notes that the Ediacaran has long been divided into distinct groupings of animals, beginning with simple stationary species that were replaced by more complex creatures emerging around 559 million years ago. Instead the new fossils reveal that these animal groups lived side by side for millions of years.