Abstract The Ordovician succession of the Korean Peninsula is part of the Cambro-Ordovician Joseon Supergroup exposed in the Taebaeksan Basin of South Korea and the Pyeongnam Basin of North Korea. This review summarizes the advances made on these successions over the past two decades, focusing on the Taebaeksan Basin. The Ordovician succession in the Taebaeksan Basin comprises the Taebaek, Yeongwol, Yongtan, Pyeongchang and Mungyeong groups, of which the Taebaek and Yeongwol groups have been studied in detail. These strata are mixed carbonate–siliciclastic deposits formed in peritidal to deep-subtidal environments. Sedimentological and palaeontological studies show that the Korean Ordovician succession represents local variations of the Great Ordovician Biodiversification Event, exemplified by reef evolution, changes in sedimentary systems and changes in invertebrate fossil assemblages. Recent studies of the Yongtan, Pyeongchang and Mungyeong groups have demonstrated that these units are important for understanding the tectonic evolution of the Taebaeksan Basin. The Ordovician strata in the Taebaek Group are generally similar to those of the Pyeongnam Basin and North China; however, the Upper Ordovician–Devonian strata between the two Korean basins show palaeontological affinities to those of South China, perhaps recording the Permo-Triassic collision between the Sino-Korean (North China) and South China blocks.

Abstract The Anti-Atlas contains a thick, volcanic-free Ordovician succession that originally deposited in a passive-margin basin. Three main sedimentary packages are bounded by major unconformities: (i) the Tremadocian–Floian Lower Fezouata and Upper Fezouata formations, which unconformably overlie a palaeorelief of Cambrian rifting volcanosedimentary complexes, and are subsequently topped by a Dapingian paraconformable gap; (ii) the Darriwilian–Katian Tachilla Formation and First Bani and Ktaoua groups, the latter unconformably overlain by a Hirnantian glaciogenic succession; and (iii) the Second Bani Group, which subsequently infilled the former glaciogenic palaeorelief. Due to the scarcity of carbonate interbeds for etching analyses, leading to rare references of conodonts, the global Ordovician chart is interpolated on the basis of microphytoplancton (acritarchs and chitinozoans), regional graptolites and brachiopods. The Ordovician counter-clockwise rotation of Gondwana led its Moroccan margin from mid- to high-latitude positions, leading to the onset of a siliciclastic, wave- and storm-dominated platform. Flooding surfaces are marked by shelly silty carbonate interbeds that reflect the episodic development of echinoderm–bryozoan meadows during Katian times; in areas protected from siliciclastic input, they reached massive and bedded bioaccumulations (Khabt-el-Hajar Formation). The Hirnantian glaciation controlled the incision of numerous tunnel channels, infilled with both alluvial to fluvial sediments and glaciomarine diamictites. The Hirnantian palaeorelief was definitively sealed during Silurian times.

Abstract Cornute stylophorans are a minor, although typical, component of Middle–Late Ordovician echinoderm assemblages adapted to soft siliciclastic substrates in high-latitude peri-Gondwanan regions. All previously reported occurrences of Darriwilian–Katian cornutes from the Czech Republic, France, Morocco and Spain are revised and their plate homologies reassessed. The genera Beryllia and Juliaecarpus are reinterpreted as junior synonyms of Domfrontia , and Thoralicystis is synonymized with Bohemiaecystis . Several Mediterranean scotiaecystids previously assigned to Bohemiaecystis and/or Scotiaecystis are placed within Thoralicarpus gen. nov., and cornute taxa originally left in open nomenclature by Chauvel are formally described as Bohemiaecystis chouberti sp. nov. (AVI) and Destombesicarpus izegguirenensis gen. et sp. nov. (AVIII). Other new Mediterranean taxa include Arauricystis clariondi sp. nov., Destombesicarpus budili gen. et sp. nov., Milonicystis reboulorum sp. nov., Thoralicarpus bounemrouensis gen. et sp. nov., and T . prokopi gen. et sp. nov. The six cornute genera identified in Darriwilian–Katian Moroccan echinoderm Lagerstätten are also present in coeval assemblages of at least one other Mediterranean region, thus supporting the existence of strong faunal affinities between the Anti-Atlas, the Armorican Massif, the Barrandian area and the Iberian Peninsula.