加拿大发现5.67亿年前最早会移动和有性繁殖的复杂生物化石

Researchers have found some of the earliest moving and sexually reproducing creatures TODAY A STRETCH OF CANADA’S remote Northwest Territories is covered in snow-capped peaks. But more than half a billion years ago this wilderness was a 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 the timeline for when these curious creatures scuttled onto the evolutionary scene. The new fossils, as described in Science Advances, also suggest that the deep sea served as an environmental cradle for complex life. …