You’re certainly on a roll with those extinction events, SVD.
Are you aware that at the start of the Younger Dryas (10,900 B.C.) there was a cataclysmic event which created the Great Lakes and set the atmosphere of North America on fire, incinerating all above-ground flora and fauna, including the so-called Clovis Indian culture?
Most likely this was an electrical discharge from another planetary body whose plasma envelope impinged upon that of Earth. The average temperature of the Earth plummeted by 18 degrees F. for the next 1,500 years as a result of ash and dust orbiting in the stratosphere. It was literally a period of darkness over the whole Earth, causing large animals to go extinct outside the tropics.