Leaders :

T. Servais (Lille, France), A. Munnecke (Erlangen, Germany), D.A.T. Harper (Copenhagen, Denmark),

Jun Li (Nanjing, China), A.W. Owen (Glasgow, UK), P.M. Sheehan (Milwaukee, USA)

Arguably the most sustained rise in marine biodiversity took place during the Ordovician, and the second largest mass extinction event took place close to the end of that Period, coincident with an episode of major climate fluctuation. The results of the very successful IGCP project n° 410 "The Great Ordovician Biodiversification Event" not only included the development of an improved globally-integrated biozonation for graptolites, conodonts and chitinozoans, but also generated biodiversity curves that have been constructed for all Ordovician fossil groups. 

Following the work of the numerous regional teams and of the clade teams, that were established for each fossil group in IGCP project n° 410, we propose a new successor project in order to develop a better understanding of the environmental changes that influenced the biodiversity trends in the Ordovician and Early Silurian. In our project, the major objective is thus to attempt to find the possible physical and/or chemical causes (e.g., related to changes in climate, sea level, volcanism, plate movements, extraterrestrial influences, etc.) of the Ordovician biodiversification, the end-Ordovician extinction, and the Silurian radiation. 

Work on understanding the patterns of biodiversity change at a range of taxonomic, spatial and temporal scales will continue through the duration of the project but our objectives in terms of understanding the environmental parameters within which these changes took place will be addressed in successive step over the five years 2004-2008:

  • the first year will focus on ocean and climate modelling, and the development of stable C-, O-, and Sr isotopes in the Lower Palaeozoic;
  • the second year will focus on the evolutionary palaeoecology of the Early Palaeozoic; 
  • in the third year, we concentrate on changing palaeogeographical patterns
  • in the fourth year, we compile all information on Early Palaeozoic events and stratigraphy
  • in the last year of our project, all information collected from the different regional teams should allow us to reconstruct Early Palaeozoic sea-level changes.

Over the five years that the project will run (2004-2008) we will organise the following major meetings in successive steps from 2004 to 2008:

  • September 2004, official opening meeting at Erlangen, Germany: ocean and climate modelling, and the development of stable C- and O-isotopes; field meeting S-Sweden (Fågelsång, Öland, Gotland); proceedings volume available as pdf files (pictures from the meeting and field trip)
  • 2005, meeting at Milwaukee, Wisconsin, USA: evolutionary palaeoecology, onshore-offshore transects;
  • 2006, meeting at Glasgow, Scotland, UK: changing palaeogeographical and palaeobiogeographical patterns;
  • 2007, 10th International Symposium of the Ordovician System at Nanjing: geological events and the stratigraphical framework; 
  • 2008, closing meeting at Lille, France: reconstruction of sea-level fluctuations and final synthesis. 
The new project will be developed in collaboration with the Subcommission on Ordovician Stratigraphy (SOS) and with the Subcommission on Silurian Stratigraphy (SSS). The understanding of the changes of the marine diversity in the Ordovician and Silurian (including the oldest and second largest of the "Big Five" Mass Extinctions) at the global level should provide us a better understanding of the evolution of life on our planet in relation to palaeogeographical and palaeoclimatical changes. 


please visit also the home page of the WOGOGOB meeting in Estonia: