Deep-water ostracods from the Middle Anisian (Reifling Formation) of the Northern Calcareous Alps (Austria)

Abstract. A diverse silicified ostracod aassemblage from Middle Anisian, Middle Triassic, intra-shelf basin deposits (Reifling Formation) is described. It comprises 32 species, of which 5 are new species (Bairdia biforis n. sp., B. schneebergiana n. sp., Mirabairdia praepsychrosphaerica n. sp., M. plurispinosa n. sp., Bairdiacypris aequisymmetrica n. sp.). The assemblage consists of both neritic species and deep-water taxa which have been considered as representatives of the ‘Thuringian Ecotype’ or the ‘Palaeopsychrospheric Fauna’. Lithofacies, palaeogeographical setting and taxonomic composition are suggestive of a deep neritic to upper bathyal depositional environment. ‘Archaic’ faunal elements are relatively rare and include the genera Spinomicrocheilinella and Processobairdia, which were formerly known only from the Palaeozoic and are now recorded for the first time from the Mesozoic.