Did you know that Earth has gone through dramatic climate shifts before? We often talk about climate change today, but our planet’s history is full of its own climate rollercoasters. A new study, looking at ancient rocks from Anticosti Island in Canada, is challenging what we thought we knew about one of these events: the Late Ordovician extinction.
This extinction, which happened around 443 million years ago, wiped out a huge portion of marine life. For a long time, scientists believed that a major cooling period, the “Early Paleozoic Icehouse,” was the main culprit, and that this cooling peaked during the extinction itself.
But this new research, using isotope data from fossils found on Anticosti Island, suggests something different. The scientists analyzed the oxygen isotopes in the shells of ancient organisms. Think of isotopes as different versions of the same element, like fingerprints. By looking at these