A Review of Volkhovian and Kundan (Arenig-Llanvirn) Nautiloids from Sweden

Well preserved nautiloid cephalopods dominate diverse macrofossil assemblages in early and mid Ordovician platform carbonates across Sweden (the so-called ‘Orthoceratite Limestone’ lithofacies). Until now these faunas have been little studied apart from pioneering works by Angelin and Holm during the last century and a few more recent papers by Troedsson, Jaanusson and Mutvei. This paper provides an updated review of Swedish Volkhovian and Kundan nautiloids assigned to the Ellesmerocerida, Endocerida, Actinocerida, Dissidocerida, Orthocerida, Tarphycerida and Oncocerida. Several taxa are key in deciphering the evolution of Ordovician cephalopods, especially early Oncocerida, Endocerida and Orthocerida, and provide further evidence for the systematic position of the lituitid nautiloids