By Susan Milius
Some of the fossils celebrated as sea life’s big breakout beyond mere soups and slimes might actually have dwelled on land, argues a controversial new study.
Named the Ediacaran fauna after Australia’s Ediacara Hills, these creatures dating from roughly 575 million to 542 million years ago mark life finally growing beyond the microscopic. Found in some 30 locations around the world, Ediacarans grew in discs, fronds and other fairly simple shapes with a quilted look, and paleontologists usually consider them some sort of marine creatures.
A new detailed analysis of the rocks where Australian Ediacarans are found suggests the rocks are fossilized soils, or paleosols, instead of a sea bottom, says Gregory Retallack of the University of Oregon in Eugene. The placement of fossils and tiny tubes in the rocks suggests to him that at least some of the Ediacarans actually lived in those soils instead of just washing up on them.