The Crucible of Creation: The Burgess Shale and the Rise of Animals, by Simon Conway Morris. Oxford University Press.
Cradle of Life: The Discovery of Earth’s Earliest Fossils, by J William Schopf. Princeton University Press.
The Burgess Shale has attained iconic status among those interested in the early history of life. It has been the subject of several books, most notably Wonderful Life, by Stephen Jay Gould, who portayed the Burgess fauna as one with a broader range of phyla, or major animal groups, than exists today. The eventual dominance of the vertebrates, he argued, was dependant on the contingencies of history, and could not have been predicted from their minor status in the Cambrian.
Morris, who has done much of the groundwork on the Burgess Shale and other Cambrian soft-bodied faunas, argues that more recent findings indicate that the diversity of Burgess phyla has been overstated, and in fact show the basic unity of groups which today we consider very distinct. The Halkieriids, for example, appear to link the molluscs, annelids, the Burgess animal Wiwaxia, and even the brachiopods.
William Schopf, on the other hand, has devoted his life to the Precambrian. A mere 30 years ago, almost nothing was known of the first three quarters of the history of life. The problem was, says Schopf, we were looking in the wrong places. Once the right kind of rocks were identified, a range of single-celled and other simple fossils were discovered, including his own record-breaking find of three and a half billion year-old cyanobacteria in Australia, the oldest fossils known.
Schopf was also brought in to advise on the purportedly fossil-bearing Martian meteorite, and he explains clearly why these structures are most likely non-biological.
Both books are highly readable accounts by leading authorities in their fields. Recommended reading.