Taxonomy and biostratigraphy of Ordovician brachiopods from northeastern Ny Friesland, Spitsbergen

摘要: We describe Early and Middle Ordovician brachiopod faunas from northeastern Spitsbergen discuss their biostratigraphical palaeoecological implications. recognise 60 species 41 genera representing both linguliform rhynchonelliform brachiopods. These include one new genus, the obolid Lenticulella with type amphora (Krause & Rowell, 1975), 23 species: Ectenoglossa? oviforma, Elliptoglossa vulgaris, Rosobolus? elongatus, Broeggeria obscura, Mirilingula? svalbardensis, Schizotreta marginalis, Conotreta convexa, Cyrtonotreta profilbekkiensis, spinosa, Eurytreta subtriangularis, Hisingerella maniformis, Semitreta basisslettaensis, pustulosa, spitsbergensis, Numericoma? proclina, Eoconulus subquadratus, Dictyonites mugilis, Pelonomia sulcata, Leptella (Leptella) inequicostellata, Protosken-idioides promontorium, Anomalorthis rossi, Nothorthis subpyramidalis Phragmorthis noda. The succession contains intertidal deep-sea deposits nearly whole range of environments. Tremadocian is represented by a low-diversity, rhynchonelliform-dominated assemblages occupying shallow-marine With abrupt large-scale drowning during Floian, these were replaced sparse slope fauna micromorphic linguliforms. outer shelf environments established in latest Floian occupied highly diverse dominated taxa. As environment shifted toward mid-shelf Darriwilian, however, composition changed to an Orthidiella-dominated assemblage mostly very late occurrence Orthidiella suggests that Dapingian Zone found America probably diachronic. Although it includes many endemic species, shows strong resemblance Nevada. This study based on approximately 16 500 specimens obtained crack-out samples acetic-acid-treated bulk samples.