Mistaken Point is a fossil site located in Newfoundland, Canada, containing some of the earliest known examples of precisely dated, well-preserved complex multicellular fossils. The fossil assemblage dates to 565 million years ago, and consists of the mysterious Ediacaran fauna – bag, spindle, bush, sea-pen (cnidarian), and frond-like organisms that lived on the deep, dark ocean floor and were finely preserved in layers of volcanic ash. As well as being the name of a type of fauna, “Ediacaran” is also a geochronological designation, as in “the Ediacaran Period”, lasting from 610 million years ago to the beginning of the Cambrian, 542 million years ago.
Mistaken Point itself is at the southernmost point of the Avalon Peninsula in Newfoundland. Here, large black cliffs overlooking the Atlantic are rich in pre-Cambrian fossils. Ediacaran fossils can be found all along the southern coast of Avalon Peninsula in great numbers, but the fossils at Mistaken Point are the most famous. The point gets its name from the over fifty shipwrecks in the area over the last few centuries.
The Mistaken Point fossils are a window into the early dawn of complex life on Earth. Living so deep underwater, these organisms would have been in a completely dark and cold environment. The volcanic ash covered the area in such a way that the Mistaken Point assemblage consists of large slabs serving as “snapshots” of what the sea floor looked like. This allows scientists to use the assemblage to study the ecology of Ediacaran organisms in a way possible nowhere else.
One aspect many of the Ediacaran fossils have in common is a quilted appearance. This has caused some paleontologists to consider the organisms related. The Ediacaran fossils found at Mistaken Point are of “unknown affinity”, meaning their relationship to the forms of life which came after is very difficult to determine. Much of the Ediacaran fauna appears to have gone extinct entirely rather than evolving into different species. By the time of the Cambrian explosion, 20-30 million years after the heyday of the Ediacaran fauna, most of the previously thriving communities were already gone. The adaptive radiation of the Cambrian led to all of the major body plans and evolutionary niches that persist to this day. Because of their abrupt termination, the Ediacaran fauna are sometimes called “a failed experiment in multicellular life.”
By Michael Anissimov