Abstract China presently comprises several independent tectonic palaeoplates or terranes and parts of other blocks, which have been assembled over geological time. In the Ordovician, these blocks included South China, North China, Tarim, Qaidam, Junggar, Qiangtang-Qamdo, Lhasa and partially Himalaya, Sibumasu and Indochina, as well as the Altay-Xing'an and Songpan-Garze fold belts, which were discrete but near-adjacent. Twelve stratigraphic megaregions bounded by tectonic sutures or major fault zones can be recognized. Some of them are further differentiated into several regions according to the lithological and biotic facies or distinct stratigraphic sequences. Here, the palaeontologic features and biostratigraphic framework of these stratigraphic megaregions and regions are summarized. The unified biostratigraphic framework presented herein is supported by 33 graptolite biozones and 27 conodont biozones, together with supplementary biozones, communities or associations of brachiopods, trilobites, cephalopods, chitinozoans, acritarchs and radiolarians. With constraints of integrative chronostratigraphy, biostratigraphy, chemostratigraphy, cyclostratigraphy and magnetostratigraphy, along with some geochronologic data, our understanding of the temporal and spatial distribution of the Ordovician lithostratigraphic units on these major blocks has been significantly advanced. Vast amounts of new data accumulated in recent decades also constrain the major Ordovician geological and biotic events evident in China, such as marine anoxia, faunal turnovers and tectonic orogenies.

Abstract This monographic study deals with a major marine faunal turnover during the Late Ordovician global greenhouse/icehouse episodes. The Late Ordovician was marked by one of the two greatest global sea-level rises and inundations of the North American paleocontinent during the Phanerozoic (last 544 million years), accompanied by a rapid diversification of invertebrate faunas in shallow, tropical, epicontinental seas. Toward the end of the Late Ordovician, continental glaciation in the southern hemisphere (Gondwana landmass) caused a major sea-level drop and marine regression from North America, bringing about the first of the five major mass extinction events in life history. Anticosti Island was part of the larger Anticosti basin, located on the eastern continental shelf of the North America paleocontinent, and was covered by a shallow, tropical sea in the Late Ordovician epoch. During the latest Ordovician global mass extinction event, the marine shelly benthos (bottom) of the Anticosti basin experienced a significant local radiation. This provides a great opportunity for us to investigate the response of marine life to a major environmental crisis. This monographic study aims to document the diversity change of brachiopods (one of the major groups of marine life during the Ordovician Period) from pre-extinction to extinction times.