Abstract Ordovician studies in Iran have shown significant progress since the beginning of the century. A number of individual faunas have been documented and a biostratigraphical framework based on conodonts, chitinozoans, acritarchs and trilobites developed. Correlation of Ordovician successions with the International Chronostratigraphic Chart has been significantly improved, and the position of the series and stage boundaries can be recognized with greater precision. While geographical proximity to temperate latitude Gondwana is apparent for most Iranian terranes, biogeographical links of Alborz and Kopet-Dagh with South China prevailed through the Early–Middle Ordovician. In Pakistan, Ordovician deposits have a restricted distribution in the Karakorum block (Chitral). Here they are represented by the Yarkhun and Vidiakot formations with Floian–Darriwilian acritarchs, chitinozoans and early Darriwilian conodonts. In Peshawar District of the North-West Frontier Province, an Early–Middle Ordovician age is likely for the Misri Banda Quartzite with Cruziana rugosa trace fossils. It is overlain conformably by carbonates of the Panjpir Formation, which has an inferred Middle Ordovician–Silurian age. Presently available information on the Ordovician of Afghanistan is mostly based on reconnaissance studies performed almost half a century ago, and a few monographed Early and Late Ordovician faunas.

Abstract Owing to the increasing availability of data for many fossil groups and a generally accepted palaeogeographical configuration, palaeontologists have been able to develop progressively more robust palaeobiogeographical scenarios for the spatial distributions of Ordovician marine faunas. However, most research in Early Paleozoic palaeobiogeography centres on data derived from extensively studied localities in North America and Europe. Thus, clear patterns are emerging of regional biogeography for these areas. However, the fragmentary nature of data from other regions hinders the development of a detailed understanding of palaeogeographical schemes of many clades at the global level. Provincial patterns are now available for several fossil groups, but the global coverage remains generally fragmentary. Palaeobiogeographical investigations were traditionally focused on better understanding of palaeogeographical scenarios and often employed quantitative analyses of faunal similarity. More recently palaeobiogeographical analyses have expanded to investigate questions such as the location and pace of speciation and macroevolution together with macroecological change. For example, studies on the evolution of speciation levels in the frame of the taxonomic radiation of the Great Ordovician Biodiversification are now available. Future investigations, including modelling, will provide more integrative, global patterns of provincialism, including the location of Ordovician biodiversity hotspots and the recognition of latitudinal diversity gradients.