Oldest 'Footprints' on Earth Found

The oldest-known tracks of a creature apparently using legs have been discovered in rock dated to 570 million years ago in what was once a shallow sea in Nevada.
Scientists think land beasts evolved from ancient creatures that left the sea and evolved lungs and legs. If the new finding is real — the discoverer anticipates skepticism — it pushes the advent of walking back 30 million years earlier than any previous solid finding....read article