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Ordovician fossils are relatively scarce in the Portuguese part of the Ossa-Morena Zone, one of the most distinctive Paleozoic domains of the Iberian Massif, where most of the available data come from the Barrancos region and needs an accurate review. The first account on the existence of Ordovician rocks near the Portuguese small city of Barrancos were published by Delgado (1901, 1908, 1910), who mentioned some graptolites and ichnofossils and defined three lithostratigraphic units from his “lower Silurian” division. In ascending order, these are the Fatuquedo shales, the Barrancos shales (including the “Phyllodocites shales” at its upper part) and the Colorada greywackes and quartzites formations. The paleontological record was virtually restricted to the fine shales of the Barrancos Fm. and especially to their “Phyllodocites shales”, a local facies of very micaceous, grey, green or red slates, not represented in the Spanish counterpart of the Estremoz-Barrancos-Hinojales domain of the Ossa-Morena Zone (Robardet et al., 1998). The age of the overlying Colorada Formation remains unknown, but graptolites recorded just above its top are already representative of the earliest Silurian (Piçarra et al., 1995). Ordovician graptolites from the Mestre André quarry east of Barrancos (Fig. 1) were first identified by Delgado (1901, p. 215) as Didymograptus geminus His., and then as Didymograptus sparsus Hopk. (Delgado, 1908 p. 187; 1910, pl. 27). New graptolite findings from the same locality were illustrated by Perdigão (1967, pl. 1, figs. 3-4), who recorded a broken stipe of D. sparsus and a proximal fragment of Didymograptus hirundo Salter, being the latter species indicative of an “upper Skiddawian” (= late Arenigian) age for the “Phyllodocites shales”.

12 páginas, 3 figuras, 3 láminas.-- Trabajo presentado en el XI International Palynological Congress. Granada, 4-9 de Jul. de 2004., A single sample from the La Matosa Member of the Barrios Formation, exposed during the excavation of the El Fabar Tunnel in Asturias, N Spain, yielded a rich and well-preserved Late Cambrian acritarch assemblage. The Middle? to Upper Cambrian La Matosa Member consists mainly of quartz sandstone and includes locally a thick fossiliferous intercalation of dark shale (“El Fabar beds”) from which the acritarch sample was collected. The latter shale levels yielded also some linguliform brachiopods, olenid trilobites and phyllocarid crustaceans. Characteristic genera of the study sample are Acanthodiacrodium, Lusatia and Cristallinium. Other significant components are Cymatiogalea, Timofeevia and Vulcanisphaera. Lusatia dendroidea Burmann 1970, recorded for the first time in Spain, is a characteristic element of this assemblage. In the study sample, the latter species is abundant, well-preserved and exhibits appreciable morphological variability. This acritarch assemblage is correlated with the lower part of microflora RA5 of Parsons and Anderson [Parsons, M.G., Anderson, M.M., 2000. Acritarch microfloral succession from the Late Cambrian and Ordovician (early Tremadoc) of Random Island, eastern Newfoundland, and its comparison to coeval microfloras, particularly those of the East European Platform. AASP Contr. Ser. 38, 129 pp.] corresponding to the Protopeltura praecursor trilobite Zone., This work was supported by a grant to Prof. G. Bagnoli (“Cofinanziamento di Ateneo”, Pisa University).