That bump in oxygen coincided with an evolutionary time known as the Ordovician radiation, or the great Ordovician biodiversification
event, when there was suddenly a lot more variety in the types of creatures that swam the Earth.
This is a contribution to the IGCP653: The onset of the Great Ordovician Biodiversification
The Ordovician is an important time of biodiversification
in shallow marine environments, which is also recorded in trace fossils (Mangano and Droser, 2004).
Our understanding of the Cambrian biodiversification
event, as well as relevant biological events prior to the Cambrian period, has been greatly clarified since 1859 by the development of radiometric dating techniques.
The Cambrian period, known for the "Cambrian Explosion" that saw the sudden appearance of all the major animal groups and the establishment of complex ecosystems, was followed by the "Great Ordovician Biodiversification
Event," when the number of marine animal genera increased exponentially over a period of 25 million years.
of the nearby orchard community tends to enhance the over-all species diversity and contributes also to the pest control by the antagonists which interfer between both the systems.
It is interesting to note that, based on molecular analyses of other groups of organisms, taxa of the high Andes and Patagonia have also been suggested as prime candidates for the impact of Pleistocene effects on biodiversification
Droser (1991) showed that the abundance of Skolithos pipe-rocks decreased after the Cambrian as a result of physical and biological factors associated with the Great Ordovician Biodiversification
Yet in terms of new species, this period cannot hold a candle to a little-known explosion of life called the Great Ordivician Biodiversification
Heterostracan vertebrates and the Great Eodevonian Biodiversification
The results were summarized in a voluminous book, The Great Ordovician Biodiversification
Event (Webby et al.
Details of the activities of IUGS/UNESCO International Geoscience Programme (IGCP) Project 591 The Early to Middle Palaeozoic Revolution--Bridging the Gap between the Great Ordovician Biodiversification
Event and the Devonian Terrestrial Revolution may be found on the IGCP 591 website (www.