You can find them on the Irish Loop. You can find them on the Bonavista Peninsula. You can even find them in downtown St John’s, if you know where to look. No, not great auk feather pillows, advocates of Newfoundland independence, or recalcitrant cod fishermen, but a more puzzling group altogether.
You could be forgiven for thinking them an alien race from a science fiction movie, but the Ediacarans aren’t here to abduct our loved ones or exterminate us all. They’ve been dead far too long for that. Instead, they’re here to show what life on Earth was like well over half a billion years ago, and, thanks to a new find made by a team of Anglo-Newfoundland palaeontologists, their already mysterious story just got a whole lot more intriguing.
Some feathery, some pizza-like, some tiny, some enormous, Ediacarans are the most distinctive fossils of the late Precambrian (630 to 542 million years ago). They take their name from the Ediacara Hills of Australia, where they were first discovered, but they are found most exceptionally in Newfoundland. The best place on Earth to admire these ancient enigmas is at Mistaken Point, on the southeastern tip of the Avalon Peninsula.
If it had only the pitcher plants on its hyper-oceanic barrens and the purple sandpipers that patrol its beaches, Mistaken Point would be remarkable enough, but the lithified life forms in its cliffs make it truly unique. Ediacarans are everywhere, and these Precambrian Problematica elevate it to the shortlist for UNESCO World Heritage Site status.
If Mistaken Point is awarded this accolade (and it really should be), the fossil-covered cliff ledges will become protected. For the moment, though, with an official guide, you can swap your shoes for blue felt boots and step tentatively onto the floor of an old lost sea, becoming a time-travelling aquanaut.
Skirt your way between the strange shapes, among the discs and fronds and shrubs, and you’ll be wondering what the heck these things were. You won’t be alone. Ediacaran biology remains uncertain, even to scientists who’ve spent their whole careers studying them. At international meetings, fierce arguments develop over the Ediacarans’ place in the tree of life: “Algae!” bellows one professor. “Lichen!” shouts another. “Chemoautotrophic vendobionts!” yells a third, just to make things complicated. One of the few things generally agreed on is that they were immobile: otherwise, they would have escaped the blankets of ash that fossilized them.
It was a revelation, a shock from the rocks. Nothing like it had ever been found before in these 565 million year-old strata: the oldest trails previously known from the fossil record were some 10 million years younger.
All of which is why the 2009 discovery by Alex Liu, a PhD student of Memorial University of Newfoundland and the University of Oxford, was so startling. On a surface a short clamber away from the main fossil site, Liu found a series of sinuous trails. Not just one or two, but dozens, meandering in many directions. It was a revelation, a shock from the rocks. Nothing like it had ever been found before in these 565 million year-old strata: the oldest trails previously known from the fossil record were some 10 million years younger.
The first explorers
We might take it for granted, especially in the helter-skelter pace of 21st century life, but locomotion is an extraordinary thing. A creature unable to move of its own volition faces a number of difficulties. It has to wait for food to drift its way, is forced to exist in a local gene pool, and is a sitting duck to being eaten by something else. Self-mobility changes everything: you can go out and see the world rather than wait for it to come and see you. The first organisms who could do it became the first explorers, and we can see where they went from the tracks they left behind.
So did Ediacarans make the Mistaken Point trails, or are these the tracks of something else? It’s hard to say. The precise bed on which they were found contains no body fossils, no convenient juxtaposition of trace and tracemaker. Conversely, none of the fossil-bearing beds nearby have yielded trails.
Liu and his colleagues, however, showed that the trails’ appearance is remarkably similar to the grooves made in mud by sea anemones on the move. This doesn’t prove that they were made by sea anemones, but it does show that something with an equivalent level of body control, and muscles, did. In short: an animal.
So not only does Mistaken Point have the most mystifying fossils, now it also has signs of animal life’s earliest movers. And if being the place where creatures first got going doesn’t pique UNESCO’s interest in preserving the site, perhaps nothing will.