This two-volume edited book highlights and reviews the potential of the fossil record to calibrate the origin and evolution of parasitism, and the techniques to understand the development of parasite-host associations and their relationships with environmental and ecological changes. The book deploys a broad and comprehensive approach, aimed at understanding the origins and developments of various parasite groups, in order to provide a wider evolutionary picture of parasitism as part of biodiversity. This is in contrast to most contributions by parasitologists in the literature that focus on circular lines of evidence, such as extrapolating from current host associations or distributions, to estimate constraints on the timing of the origin and evolution of various parasite groups. This approach is narrow and fails to provide the wider evolutionary picture of parasitism on, and as part of, biodiversity. Volume one focuses on identifying parasitism in the fossil record, and sheds light on the distribution and ecological importance of parasite-host interactions over time. In order to better understand the evolutionary history of parasites and their relationship with changes in the environment, emphasis is given to viruses, bacteria, protists and multicellular eukaryotes as parasites. Particular attention is given to fungi and metazoans such as bivalves, cnidarians, crustaceans, gastropods, helminths, insects, mites and ticks as parasites. Researchers, specifically evolutionary (paleo)biologists and parasitologists, interested in the evolutionary history of parasite-host interactions as well as students studying parasitism will find this book appealing.