Progress in paleoanthropology is impeded when new fossil materials are published but unavailable for comparative study, as is too often the case. In this commentary, we review the stages of description and analysis that new fossils must undergo and conclude that it is disingenuous to argue that fossils have not been properly "published" when descriptions and new names formulated in accordance with the International Code of Zoological Nomenclature have appeared in leading scientific journals. Once such names and descriptions have been published, it is imperative that the original fossils concerned be available to the scientific community for comparative analysis, for by the very nature of science, no statement about such fossils, however carefully prepared by the original describers (or anyone else), can be regarded as definitive. Science is a system of provisional knowledge that constantly requires re-examination and testing. It cannot function as a system in which assertions have to be left unchallenged for want of free access to the primary data. Copyright 2002 Wiley-Liss, Inc.