地球的歷史已經(jīng)有45億年了.在距今約束38億年前出現(xiàn)了最早的生物.從那時起,地球上的很多生物經(jīng)歷了興起、衰落直至滅亡的歷程,只有化石留存至今.現(xiàn)在世界各地都能找到各個時期不同種類的化石,這些化石告訴了我們地球滄海桑田的變遷歷史.
距今兩億多年前,地球上曾經(jīng)生活著一群生物——恐龍.它們盛極一時,稱霸地球達(dá)成1.5億年之久.
在人類出現(xiàn)以前,恐龍就已經(jīng)滅絕了,沒有人見到過活的恐龍.今天我們所知道的有關(guān)恐龍的一切是從恐龍的化石得來的.由于人們找到了它們的骨、齒、卵的化石,和皮膚痕跡、腳印、穴居場所等,科學(xué)家們就根據(jù)這些線索去探索有關(guān)恐龍的秘密.
The Earth's history has been 45 billion years.Constraints in the 38 million years ago before the emergence of the earliest organisms.Since then,much of the planet has experienced the rise of biotechnology,the course of the decline until extinction,only the fossils so far retained.Now the world can be found in various periods of different types of fossils,these fossils tell the history of our planet earth-shaking changes.
Dating back more than 200 million years ago,life on Earth has a group of organisms - the dinosaurs.They are very popular and dominate the Earth to reach 1.5 million years old.
In humans before the advent of dinosaurs had become extinct,and no one to see live dinosaurs.Today,we know everything about dinosaurs from the dinosaur fossils come.As people found their bones,teeth,egg fossils,and skin marks,footprints,and other cave sites,the scientists on the basis of these clues to discover the secrets of the dinosaurs.