Yukon fossils reveal earliest traces of animal lifeVancouver Sun: Microscopic fossils at Mount Slipper, a 1,500-metre peak north of Dawson City near the Yukon-Alaska border, have been dated to nearly 800 million years ago... That situates the fossil bed at a crucial time in Earth history, when primitive, unicellular forms of life were beginning to evolve more complex structures ahead of the rise of mobile, Ediacaran-era organisms 600 million years ago and the Cambrian-age 'explosion' of larger and more diverse animal species about 500 million years ago...
These microfossils are perhaps the earliest eukaryotic 'biomineralizers' -- the first organisms to incorporate minerals in their body to form a shell of sorts,' [said] 'Harvard University geologist Francis Macdonald, lead author of the study...
Macdonald said Mount Slipper and nearby sites in Yukon and Alaska 'preserve some of the best records in the world of Earth history between one billion and 540 million years ago, which captures the time of eukaryotic diversification and the origin of animals.' The fossil records in the area 'are complete, organic rich, and contain volcanic ashes, which allow us to calibrate the age of our discoveries.' he added.
Canada's unrivalled geological diversity -- including some of the world's oldest rocks and vast tracts of exposed fossils -- attracts many international researchers working to record the story of evolution as it unfolded at microscopic scale in the dawning era of life. In the same edition of Geology in which the Macdonald-led study appears, a team of British and Canadian paleontologists reported the discovery in Newfoundland of the oldest evidence of animal locomotion -- a 565-million-year-old fossilized trackway of an unidentified, sea anemone-like marine creature...
Last year, a team of Canadian and US scientists reported a major discovery in the Mackenzie Mountains near the Yukon-Northwest Territories border. They found chemical traces left by what they believe to be an 850-million-year-old, spongelike organism -- possibly the oldest evidence of an animal ancestor ever found on Earth.
