PaleoBase is a new initiative in the presentation of systematic information on fossil organisms. It represents the marriage of up-to-date systematic information on a collection of over 1500 fossil genera, state-of-the-art color digital photographs of representative specimens from The Natural History Museum's unrivaled paleontological collections, and modern relational database technology. With PaleoBase an important new tool for the teaching of life history in a wide variety of advanced secondary, undergraduate and graduate courses (e.g., paleontology, historical geology, stratigraphy, paleoceanography, paleobiogeography) becomes available to students and educators alike. PaleoBase: Macrofossils is the first product from the PaleoBase project, and will be released in three Parts. It will consist of approximately 1000 generic records drawn from the major invertebrate groups. The genera have been carefully selected to include taxa used in the teaching of paleontology and historical geology worldwide. Together they represent the ideal fossil collection, one that in practice only the largest natural history museums could hope to assemble. PaleoBase: Macrofossils gives educators, students and researchers access to a virtual collection of these fossils - many of which are actual figured specimens from the 19th and 20th century technical publications that served to originally establish the concepts of these genera. PaleoBase: Macrofossils Part One contains data on the Arthropods (non-Trilobite), Brachiopods, Bryozoans, Graptolites, Trace Fossils and Trilobites. Part Two contains Bivalves, Gastropods, Ammonoids, Nautiloids, Coleoids and Early Metazoans. Part Three will cover Cnidaria, Echinoderms, Sponges, 'Other' fossil groups. For an online demonstration and guided tour of PaleoBase: Macrofossils please visit: www.paleobase.com