The diversity of modern snakes appeared during the Paleocene epoch ("c" 66 to 56 Ma ago, after the Cretaceous–Paleogene extinction event).
A wide range of snakes appeared during the Paleocene period ("c" 66 to 56 million years ago).
A wide range of snakes appeared during the Paleocene period ("c" 66 to 56 million years ago).
使用更简单的措辞: The diversity of modern snakes appeared during the Paleocene epoch ("c" 66 to 56 Ma ago, after the Cretaceous–Paleogene extinction event). 输出: