A MYSTERY is afoot. Something appears to have been crawling over the seabed more than a billion years ago. Yet according to the textbooks, animals didn’t exist until hundreds of millions of years later.
The puzzle originates from some fossilised trails found in Australian rock. The ridges are a millimetre wide and up to 2 milli-metres apart, and look like slime trails left by some worm-like creature inching across fine sea-floor mud.
When geologists found the trails 10 years ago, they assumed that the rocks must date from the Ediacara epoch 550 to 600 million years ago—the time from which…
