The dry mountain ranges of the western United States contain rocks dating back 440 to 510 million years, to the Ordovician period, and teeming with evidence of tropical marine life.
美国西部干燥的山脉包含了距今4.4亿至5.1亿年前的奥陶纪岩石，其中充斥着热带海洋生物生存的迹象。
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Current worst case predictions suggest that tropical coral reefs, which have evolved over millions of years, will be functionally extinct within the next 30 to 50 years.