Ordovician Paleogeography: The Possibilities and Constraints of Conodont-Based Biogeographic Reconstructions

Abstract This paper provides an overview of modern global paleobiogeographic reconstructions for the Ordovician period and regional paleogeographic patterns of the structures of the East European Platform and the western part of the Central Asian Fold Belt. The history of the development of ideas about the conodont biogeography and their studies is outlined. It is shown that the biogeography of the Ordovician conodonts follows the principles of biogeographic zonation of the modern ocean allowing identification of areas/kingdoms of the open sea and shallow seas as main biogeographic subdivisions. It is shown that the biogeography of pelagic conodont faunas in the Ordovician is determined by climatic zonation. The biogeography of the shallow-sea faunas is confirmed by the level of endemicity of pelagic conodont faunas, which makes it possible to assess the mutual geographical location of paleobasins. The contribution of the conodont-based biogeographic zonation to the development of ideas about the paleogeography of the East European Platform and the western part of the Central Asian Fold Belt is shown.