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The boundaries and subdivisions of the global Dapingian stage cannot be adequately characterized in the extensive south-polar Gondwana continental shelves. Correlatable sediments, dated to some extent by palynomorphs, are generally highly condensed in shale facies ( < 10 m thick) or are entirely lacking, whereas in shallow-water sandstones they may locally reach more than 100 m thick. In the absence of valuable data derived from key macrofossils (graptolites and conodonts), the regional chitinozoan biostratigraphy has gone through numerous conceptual variations in the last 20 years, which has not helped a precise definition of the base of the Dapingian, provisionally included in the “upper” Arenigian regional stage of peri-Gondwana. [ABSTRACT FROM AUTHOR]

The study of a brachiopod collection from the Queixopêrra Member of the Cabeço do Peão Formation (Upper Ordovician), in Portugal, has provided a low-diversity association composed exclusively of draboviids. The commonest components in this association areDraboviacf.reduxandHirnantia kinnelloides, both only known until now from the Letná Formation (Sa2), Bohemia (Czech Republic). The occurrence ofH. kinnelloidesin the Queixopêrra Member (Ka1) constitutes the youngest known occurrence of this taxon, which extends its stratigraphical range and strengthens the palaeogeographical relationship between Portugal and the Bohemian region during the early Late Ordovician. [ABSTRACT FROM AUTHOR]