In North America in the Northern Plains of the United States and the Southern Plains of Alberta and Saskatchewan, there's this unit of rock called the Hell Creek Formation that produces the last dinosaurs that lived on Earth.
在北美洲，美国的北部平原 和加拿大的阿尔伯塔及萨斯喀彻温省南部平原 有一种叫做“地狱溪地层”的岩石群 在那里发现了最晚生活在地球上的恐龙化石