Animals may have evolved 200 million years earlier than we thought

New research suggests animals could have evolved as early as 800 to 700 million years ago, roughly 200 million years earlier than some previous estimates. If so, the first animals may have lived before or during Snowball Earth, leaving behind little trace because their soft bodies were rarely preserved. Animals may have evolved 200 million years earlier than we thought.

A study led by the University of Oxford suggests the earliest animals may have existed hundreds of millions of years before the first unmistakable animal fossils appear. 2 in Science Advances, indicate that animals could have originated deep in the Neoproterozoic Era, possibly before some of the most severe ice ages in Earth’s history. The research could reshape scientists’ understanding of a major evolutionary puzzle.

Animals seem to appear relatively abruptly in the fossil record shortly before the Cambrian Period (539 to 487 million years ago), even though other lines of evidence have long suggested their evolutionary story began much earlier. At the center of the new study is a question about how researchers have used ancient fossil deposits to place a maximum age on the origin of animals. Rethinking a key fossil assumption One important site is the Weng’an Biota in China, a roughly 590 million year old fossil deposit preserved in rocks of Ediacaran age.