A snapshot of an ancient seafloor
The cliffs at Mistaken Point are a series of tilted rock slabs that were once the bottom of a deep ocean, more than 565 million years ago during the Ediacaran Period. Today, these surfaces are covered with the impressions of thousands of fossils. The organisms were soft-bodied, meaning they had no shells or bones to fossilize. Their exceptional preservation is due to periodic burials by fine volcanic ash that rained down through the water column. These ash layers smothered the seafloor communities, creating molds of the organisms where they lived—an "Ediacaran Pompeii."
The fossils belong to a group of organisms known as the Ediacaran biota, the earliest known large and complex life on Earth. More than 30 distinct species have been identified here. Many of the organisms are rangeomorphs, an extinct group with a fractal-like, branching body plan that resembles a fern or a spindle. These creatures lived in total darkness on the deep seabed, far below the reach of sunlight, which rules out any form of photosynthesis. The individual fossils range in size from a few centimeters to nearly two meters in length. Important species found here include the frond-shaped Charnia masoni and the spindle-shaped Fractofusus misrai.
An evolutionary dead end?
The biology of the Ediacaran organisms from Mistaken Point is a subject of scientific debate. They appear to lack any of the features common to animal life today, such as mouths, digestive tracts, or organs for movement. This has led to several hypotheses about their nature. Scientists propose they were early, primitive animals, perhaps related to sponges or cnidarians. Others suggest they could have been a form of fungi or even a completely separate kingdom of life, a failed evolutionary experiment that went extinct before the Cambrian Explosion.
The site is important for its preservation of entire communities in place. More than 100 fossil-bearing surfaces have been exposed by erosion, allowing scientists to study the ecological structure of this ancient ecosystem. The first fossils at the site were discovered in 1967 by Shiva Balak Misra, a graduate student from Memorial University. At the time, his find was largely overlooked. Today, the location is recognized as a UNESCO World Heritage Site, inscribed in 2016, protecting a 17-kilometer stretch of coastline. The site contains over 10,000 individual fossil impressions, more than the sum total of all related museum collections on Earth.