In 1997, IGCP Project No. 410 was established to appraise known records of Ordovician biotas, in order to evaluate one of the greatest-ever diversifications of life on Earth, between 489 and 443 million years ago. Data collection and analysis of biodiversity were coordinated through seven regional teams, and a global "clade" team. A web-based relational database was employed for input of results. Some 200 workers from 38 countries participated, resulting in approximately 1,000 publications. Global and/or regional diversity trends were determined for most fossil groups down to species level, and many other relevant aspects such as bioevents, biofacies, impacts of changing geographic and environmental regimes, and ocean and climatic states were studied. A new, highly resolved, well-calibrated, and wholly integrated Ordovician timescale was established to allow precise local- to global-scale correlations of biodiversity data, and a standardized set of diversity measures developed to provide a consistent basis for communicating biodiversity results. The global Ordovician Radiation exhibited more-or-less uninterrupted biodiversity increase from the beginning of Ordovician time, but was punctuated by dramatic, more intensive, step-wise pulses of diversification through the Mid to Late Ordovician, prior to the glacially induced End Ordovician mass extinction. The events included a bewildering array of adaptive radiations of Cambrian-, Palaeozoic- and Modern-type evolutionary biotas in marine habitats, the first animals (arthropods) to walk on land, and the first plants (non-vascular bryophytelike forms, based on cryptospore records) to colonize damp sites on land-all of these pivotal in shaping future evolutionary pathways.
|Number of pages||6|
|Publication status||Published - Sep 2004|