摘要：The fossil record is immense. Consid- ered as a whole, it is an astounding array of organic remains, making up the raw data for our reconstruction of the history of life on this planet. Although it is undeniably a fragmen- tary dataset, deeply biased in its repre- sentation of biological and ecological diversity, scientists have yet managed to extract from it the framework of a compelling story that spans more than three-and-a-half billion years.
