Three Decades (1997–2026) of Igcp (international Geoscience Programme) Projects to Decipher the GOBE (great Ordovician Biodiversification Event) 30

Since 1972, the International Geoscience Programme (IGCP) has aimed to facilitate international scientific cooperation in the field of geosciences. Launched originally as the International Geological Correlation Programme, its name was changed in 2015, but the acronym IGCP remained to allow continuity. Over the past five decades, IGCP projects have been sponsored by the International Union of Geological Sciences (IUGS) to bring together thousands of Earth scientists from around the world and allowed them to benefit from the cooperative spirit generated under the umbrella of the United Nations Educational, Scientific and Cultural Organization (UNESCO). Over the past three decades, a total of five IGCP projects devoted to the Ordovician radiations, were organized by various Ordovician experts from different countries, ratified by UNESCO and conducted in many countries and regions in the world, to facilitate research cooperation among geoscientists across frontiers and national boundaries, through joint research work, meetings and workshops, to understand the Ordovician radiations. Each project emphasized different elements of the Ordovician radiations, today generally known as the Great Ordovician Biodiversification Event (GOBE). All five Ordovician IGCP projects were closely associated with the Subcommission on Ordovician Stratigraphy (SOS), and many of their co-leaders also served as executive or titular members of the SOS. IGCP 410 ran from 1997 to 2002 and coined the term Great Ordovician Biodiversification Event. The major achievement of this project was the establishment of regional teams and taxon-specific (“clade”) teams, resulting in biodiversity curves produced by almost all fossil groups, summarized in the land-mark publication known as the ‘Webby book’ (2004). IGCP 503 followed from 2004 to 2009 to look for the triggers of the GOBE, in particular the palaeogeographic and palaeoclimatic drivers. IGCP 591 (2012-2016) extended this work by bridging the gap between the GOBE and the Devonian Terrestrial Revolution, whereas IGCP 653 (2016-2021) attempted to find the roots of the GOBE, concentrating on its onset in the Cambrian. Collectively, these projects demonstrated the complexity of the GOBE and highlighted both strengths and limitations of the biodiversity databases employed. IGCP 735 (2021-2026), therefore, attempts to fill the numberous knowledge gaps in data for the Early Palaeozoic Biodiversification. Based on the collaborative research work by several hundreds of scientists, including (graduate and undergraduate) students, from all parts of the world, in the frame of the five IGCP projects over the last three decades, the ‘Great Ordovician Biodiversification Event’ became a well-known term, that is today largely used, also by the general public, similar to the ‘Cambrian Explosion.’