Geology 38, 123–126 (2010)

Fossilized paths suggest that, 565 million years ago, animals actively moved around — the oldest evidence for locomotion yet.

Alexander Liu at the University of Oxford, UK, and his colleagues describe narrow tracks up to 17.2 centimetres long found in mudstone slabs from Mistaken Point in southeastern Newfoundland, Canada. The slabs, once part of a sea floor one kilometre deep, are believed to preserve remnants of bottom-anchored suspension feeders.

The discovery suggests that these organisms moved to forage or avoid environmental stresses in a period before the 'Cambrian explosion' of invertebrate animals, which began some 20 million years later.