The Reason Behind The Mass Extinction 420 Million Years Ago On Earth

About 550 million years ago was the time when life on Earth officially began. Since the Cambrian Explosion and through many other periods of the geological timeline, there had been the existence and extinction of many species. In particular, in the mass extinctions, which was considered as the "asteroid that killed the dinosaurs", many creatures permanently disappeared.

One of such major extinctions was the Lau/Kozlowski that occurred nearly 420 million years ago in the Silurian period and destroyed nearly 23 percent of marine life. However, the cause of the event has not been clarified. According to a publishment on Science Direct, there was proof of the immediate decrease in oxygen concentration in the ocean, and therefore, it is the culprit of the mass extinction mentioned above. This event then caused a disturbance of the carbon cycle because of rising organic matters. As a result, the climate has changed dramatically since then.

We know that extinction events are all connected to each other. For example, before the mass extinction nearly 100,000 years, there was a disruption of the carbon cycle. As such, to develop a timeline between the oxygen deterioration, Lau/Kozlowski extinction as well as the carbon cycle depletion, scientists had to collected datasets relating to thallium isotope, manganese isotope and sulfur from specific locations in Sweden and Latvia.

According to Seth Young, The Assistant Professor at Florida State University and co-author of the study on Science Direct, this study has a practical meaning that helps to explore the rapid decline of biodiversity and its impact to the environment, which is happening very intensively at present. Also in the study, the authors concluded that oxygen deterioration, starting in the deep sea and eventually spreading into shallow parts, was the cause of the mass extinction on Earth.