Researchers say they've found what may be the Earth's oldest animal in the Mackenzie Mountains of the Northwest Territories.
The primitive sponge-like creature, traces of which were discovered by paleontologist Elizabeth Turner and two other scientists, may well push back the earliest geological signs of animals by more than 200 million years.
"We're not looking at things that are as complicated as worms or even as complicated as sponges," Turner, of Laurentian University in Sudbury, Ont., told CBC News.
"We're looking at something that's simpler than that. And that's at the very junction between the earlier life forms that preceded animals and the lineage that became animals."
The trio's discovery has been documented in this month's issue of the journal Geology.
Only a few months earlier, evidence from the Arabian Peninsula pushed back the origins of animal life to 635 million years ago.
The new find by Turner and her colleagues dates those origins even further in the past, by another 200 million years.
"It is a big deal because, I mean, there's a huge community out there of people who are trying to understand the early evolution of animals and the early evolution of Earth ecosystems," she said.
Alasdair Veitch, a biologist in Norman Wells, N.W.T., said the discovery of the sponge-like body is an example of the rapid progress scientists have made in mapping human evolution.
"These little sponges that were on the sea floor out in the Mackenzie Mountains 850 million years ago — those are the precursors to all the caribou and sheep and moose and even ourselves that [are] what we have today," he said.