人类最宏伟的建筑,能历经千年;最古老的人类制品,能存留万年乃至百万年,然而这些和地球历史(46亿年)和生命演化史(36亿年)相比显得十分短暂;即使是动物中较晚出现的哺乳动物也有2亿多年的演化历史,远远超出任何人类制品的存留寿命。我们要了解远古的哺乳动物,只能通过保存在地层中历经漫长岁月的骨骼化石。在哺乳动物1亿多年漫长的演化过程中,大量的生命淹没于时间长河之中,只有不到万分之一的生物在死亡后经历了搬运、埋藏和化 The most magnificent buildings in mankind can last for thousands of years; the oldest artifacts can last for thousands of years or even millions; however, these are short-lived compared with the history of the Earth (4.6 billion years) and the evolution of life (3.6 billion years) Even the later mammals in animals have an evolutionary history of more than 200 million years, far exceeding the lifespan of any human product. We need to understand the ancient mammals, only through the fossilized bones preserved in the strata over a long period of time. During the long evolution of mammals over 100 million years, a great deal of life is submerged in time, and less than one in 10,000 organisms have undergone handling, burial and integration