Hundreds of millions of years ago, in the middle of what would eventually become Canada’s Yukon Territory, an ocean swirled with armored trilobites, clam-like brachiopods and soft, squishy creatures akin to slugs and squid. A trove of fossils and rock layers formed on that ancient ocean floor have now been unearthed by an international team of scientists along the banks of the Peel River a few hundred miles south of the Arctic’s Beaufort Sea. The discovery reveals oxygen changes at the seafloor across nearly 120 million years of the early Paleozoic era, a time that fostered the most rapid development and diversification of complex, multi-cellular life in Earth’s history. “It’s unheard of to have that much of Earth’s history in one place,” said Stanford University geological scientist Erik Sperling, lead author of a July 7 study detailing the team’s findings in Science Advances. Most rock formations from the Paleozoic Era have been broken up by tectonic forces or eroded over time. “There’s nowhere else in the world that I know of where you can study that long a record of Earth history, where there’s basically no change in things like water depth or basin type.” - Geology Page