I am pleased to be able to introduce this book by Monsieur lean-Claude Gall, firstly because it is a book, secondly because its author has been a colleague for 15 years, and finally because it is a book which demonstrates the growing importance of Palaeobiology. "Because it is a book." I have already commented else where on the value which the Earth Science community places on a book. And here I am speaking, not of a thesis or a specialised memoir, which are always precious, but of a manual or text, which draws on the experts in the service of all. In the years preceding and following the...