The late Triassic period (2-2 million years ago) is said to be an era of repeated extinctions of living things.Recent studies have shown that marine organisms such as ammonites, propellants, and conodons, which are often found during this period, experienced great extinction about 3700 million years ago, due to the giant meteorite. Research groups at Kumamoto University, Ocean Research and Development Organization, Kochi University, Tokyo University, Niigata University, and Chiba Institute of Technology have identified the fact that they are in conflict, and published the results in the British scientific journal "Scientific Reports."
In 2013, the research group discovered evidence that a giant meteorite with a diameter of 3.3 to 7.8 km collided with the earth from a clay rock called "chart" in Gifu prefecture. I didn't know if it had any effect.This time, as a result of extracting radiolarian and conodont fossils from the late Triassic chert and examining the extinction pattern of the fossil population, it was discovered that these fossil communities were extinct immediately after the impact of the meteorite.
Furthermore, when we investigated the fluctuations in the production of phytoplankton and radiolarians, which are zooplankton, during this period, the production of phytoplankton decreased significantly over the tens of thousands of years after the meteorite collision, and the production of phytoplankton (radiolalaria) was accompanied by this. ) Was also declining.Radiolarian production did not return to its original level for about 30 years, during which time new radiolarian communities that did not exist before the meteorite impact emerged and most of the old communities were extinct. It turned out that.
Previous studies have suggested that the only large-scale extinction of organisms due to impacts of meteorites was the extinction of dinosaurs 6600 million years ago, but in this study, impacts of meteorites long before that were the marine ecosystems at that time. Was found to have collapsed.
In the future, the group will search for what was formed by the meteorite impact from the late Tritatian strata around the world, and study what kind of organisms were extinct by this meteorite impact.At the same time, it plans to proceed with research on changes in the global environment caused by meteorite impacts such as cooling and acid rain.
