From the enormous bones of the blue whale to the microscopic plates of marine algae to the planetary-scale accumulations of coral reefs, skeletons underpin much of life on Earth. But when and why did skeletons form, and how did they provide a durable framework for evolution? Mark Williams and Jan Zalasiewicz tell the billion year-scale story of skeletons on Earth, consider how the warp-speed evolution of techno-skeletons is now shaping our planet’s future, and explore the possibilities of skeleton formation on other planets. They show that there is much more to skeletons than a lot of old bones. Mark Williams is a palaeobiologist at Leicester University. He researches into some of the major biological events in the 4-billion year evolution of life on Earth. His work has taken him from the Antarctic wilderness to the dense tropical rain forests of East Asia, and from studying the origins of animals 500 million years ago, to examining the significant and recent human-induced changes to the biosphere.