Abstract Anomalocystitid mitrates represent one of the most diverse and long ranging clade of stylophorans (Early Ordovician–Middle Devonian). Although they probably originated from a peri-Gondwanan stock of early mitrocystitids during the Floian, the fossil record of anomalocystitids in the Middle–Upper Ordovician of the Mediterranean Province remains extremely scarce and largely underestimated. The unusually shaped anomalocystitid genus Diamphidiocystis was originally described in the latest Katian–Hirnantian of North America (Illinois). However, earlier occurrences of this genus in the late Darriwilian of western France (Brittany) suggest a probable peri-Gondwanan origin. Based on new Middle to Late Ordovician material from the Anti-Atlas (Morocco), Bohemia (Czech Republic) and Brittany (France), all occurrences of Mediterranean Diamphidiocystis are considered as conspecific and formally described as D. regnaulti sp. nov. The palaeobiogeographical significance of Ordovician anomalocystitid mitrates is discussed.

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.

Abstract In the abandoned slate quarry of Guernanic, Gourin (Morbihan, France), a single horizon (Upper Member of the Schistes de Postolonnec Formation) has yielded an exquisitely preserved Llandeilian (Middle Ordovician) echinoderm assemblage composed of the ophiuroid Taeniaster armoricanus sp. nov. and the mitrate Mitrocystella incipiens. These two groups of echinoderms represent the first fossils formally described from the Middle Ordovician of the Gourin area. The brittlestar T. armoricanus sp. nov. is the third and oldest ophiuroid reported so far in the Palaeozoic of the Armorican Massif. The mitrate Mitrocystella is also described for the first time from western Brittany. Taphonomic features of this ophiuroid–stylophoran aggregation suggest that it probably corresponds to the rapid burial of a life assemblage in an otherwise quiet and moderately deep setting (shelf) below, but close to, storm wave base. This echinoderm association represents the oldest evidence for a gregarious mode of life for ophiuroids, as well as the oldest indisputable example of a mixed ophiuroid–stylophoran meadow.

Abstract The Ordovician successions of France and neighbouring areas of Belgium and Germany are reviewed and correlated based on international chronostratigraphic and regional biostratigraphic charts. The same three megasequences related to the rift, drift and docking of Avalonia with Baltica can be tracked in Belgium and neighbouring areas (Brabant Massif and Ardenne inliers), western (Rhenish Massif) and northeastern Germany (Rügen). The remaining investigated areas were part of Gondwana in the Ordovician. The Armorican Massif shares with the Iberian Peninsula a Furongian–Early Ordovician gap (Toledanian or Norman gap), and a continuous Mid–Late Ordovician shelf sedimentation. The Occitan Domain (Montagne Noire and Mouthoumet massifs), eastern Pyrenees and northwestern Corsica share with southwestern Sardinia continuous shelf sedimentation in the Early Ordovician, and a Mid Ordovician ‘Sardic gap’. In the Ordovician, the Maures Massif probably belonged to the same Sardo-Occitan domain. The Vosges and Schwarzwald massifs display comparable, poorly preserved Ordovician successions, suggesting affinities with the Teplá-Barrandian and/or Moldanubian zones of Central Europe.

Abstract The early Late Ordovician (Sandbian 1) representatives of the Tafilalt Biota in the locality of Bou Nemrou (Jbel Tjarfaïouine) provide examples of fossil preservation in medium-grained sandstones with abundant microbially induced sedimentary structures. The recorded trilobite assemblage comprises 11 species of ten genera, among which one is new (Placoparia africana Pereira & Gutiérrez-Marco, sp. nov.) and four others previously regarded as endemic to the locality are considered to be synonymys of species already described from Bohemia. The oldest representative of the illaenid genus Cekovia is recorded, revised diagnosis proposed for the genus Mytocephala Struve and for Uralichas tardus Vela & Corbacho. Parvilichas Corbacho & Vela is considered to be a junior synonym of Uralichas Delgado. From a palaeobiogeographical point of view, the Bou Nemrou locality shows strong relationships with trilobite assemblages from the Dobrotivian and with the lower Berounian sandstone facies of Bohemia, reinforcing the correlation of both regions. Some soft-bodied structures are recognized here, including the digestive tracts of Uralichas and the traces of paired, metameric axial bands in the anterior thoracic segments of the trilobite Selenopeltis preserved in apatite and interpreted as intersegmental musculature.