@article{Kröger_Pohle_2021, title={Early-Middle Ordovician cephalopods from Ny Friesland, Spitsbergen – a pelagic fauna with Laurentian affinities}, volume={783}, url={https://europeanjournaloftaxonomy.eu/index.php/ejt/article/view/1601}, DOI={10.5852/ejt.2021.783.1601}, abstractNote={<p>The collection of cephalopods from eight sampling horizons within the Olenidsletta Member, Valhallfonna Formation, Floian–Dapingian, from Profilstranda and nearby Profilbekken, Ny Friesland, Spitsbergen, resulted in the detection of 31 species, 20 genera, and 12 families from the Ellesmerocerida, Endocerida, Riocerida, Dissidocerida, Orthocerida, Tarphycerida, and Oncocerida. Of these, five genera (<em>Ethanoceras</em> gen.&nbsp;nov., <em>Hinlopoceras</em> gen.&nbsp;nov., <em>Nyfrieslandoceras</em> gen.&nbsp;nov., <em>Olenidslettoceras</em> gen.&nbsp;nov., <em>Svalbardoceras</em> gen.&nbsp;nov.) and 19 species (<em>Bactroceras fluvii</em> sp.&nbsp;nov., <em>Buttsoceras buldrebreenense</em> sp.&nbsp;nov., <em>Cycloplectoceras hinlopense</em> sp.&nbsp;nov., <em>Cyclostomiceras profilstrandense</em> sp.&nbsp;nov., <em>Deltoceras beluga</em> sp.&nbsp;nov., <em>Eosomichelinoceras borealis</em> sp.&nbsp;nov., <em>Ethanoceras solitudines</em> gen. et sp.&nbsp;nov., <em>Hemichoanella occulta</em> sp.&nbsp;nov., <em>Hinlopoceras tempestatis</em> gen. et sp.&nbsp;nov., <em>H. venti</em> gen. et sp.&nbsp;nov., <em>Lawrenceoceras ebenus</em> sp.&nbsp;nov., <em>L. larus</em> sp.&nbsp;nov., <em>Litoceras profilbekkenense</em> sp.&nbsp;nov., <em>Nyfrieslandoceras bassleroceroides</em> gen. et sp.&nbsp;nov., <em>Olenidslettoceras farmi</em> gen. et sp.&nbsp;nov., <em>Protocycloceras</em> <em>minor</em> sp.&nbsp;nov., <em>Proterocameroceras valhallfonnense</em> sp.&nbsp;nov., <em>Svalbardoceras sterna</em> gen. et sp.&nbsp;nov., <em>S. skua</em> gen. et sp.&nbsp;nov.) are new. The diagnoses of the Cyptendoceratidae, Bactroceratidae and of <em>Deltoceras</em> Hyatt, 1894 are emended. Well preserved early growth stages in several species are remarkable. Turnover between the sampling horizons and between sampling intervals is high. The differences in composition, diversity and evenness of the assemblages are interpreted as reflecting changing depth and oxygenation depositional bottom conditions. The co-occurrence of endemic and cosmopolitan species is interpreted as resulting from a high vertical niche differentiation and from eustatically generated lateral shifts of facies zones. Based on calculations of phragmocone implosion depths, depositional depths of 50–130 m are plausible for the Olenidsletta Member, supporting independent evidence from biomarker signatures. Several cephalopod species of the Olenidsletta Member represent odd mosaics of morphological features of previously known cephalopods which cannot be unambiguously assigned to one of the existing cephalopod higher taxa. Results from a cladistic analysis shed new light on the early evolution of the Oncocerida and Orthocerida.</p>}, number={1}, journal={European Journal of Taxonomy}, author={Kröger, Björn and Pohle, Alexander}, year={2021}, month={Dec.}, pages={1–102} }