To reach that surprisingly conclusion, scientists studied the positions of 21 asteroid impact craters during the Ordovician period – the second of six periods in the Paleozoic...

To reach that surprisingly conclusion, scientists studied the positions of 21 asteroid impact craters during the Ordovician period – the second of six periods in the Paleozoic Era that spanned 41.6 million years, from roughly 485.4 million years ago to about 443.8 million years ago.

Study: https://www.sciencedirect.com/science/article/pii/S0012821X24004230