It is animals and plants which lived in or near water whose remains are most likely to be preserved, for one of the necessary conditions of preservation is quick burial, and it is only in the seas and rivers, and sometimes lakes, where mud and sit have been continuously deposited, that bodies and the can be rapidly covered over and preserved.

　　只有生活在水中或水边的动植物尸体最有可能被保存下来，因为保存的必要条件之一是迅速掩埋，所以只有在泥沙不停淤积的海洋和江河里，有时在湖泊里，尸体之类的东西才能被迅速地覆盖而保存下来。