An American geologist has found what scientists said could be the world’s oldest animal fossil, the outline of a jellyfish-like creature that lived on the sea floor up to 600 million years ago.
Mark McMenamin of Mount Holyoke College made the discovery in March in the Mexican desert, about 100 miles south of Tucson, Ariz. He was hiking when he came across the fossils, etched in sandstone and shale lying exposed on the desert floor.
The fossil shows the 2-inch-long form of a new species of Ediacaran biota, which are among the oldest creatures that can be considered animals, McMenamin said. The fossil clearly shows a central bell, like on a jellyfish, with apparent tubes radiating outward.