New late Smithian (Early Triassic) ammonoids from the Lusitaniadalen Member, Vikinghogda Formation, Svalbard

Abstract

A single carbonate concretion from the uppermost Lusitaniadalen Member (‘Fish Niveau’, Vikinghøgda Formation) at Stensiöfjellet, Spitsbergen, contains a fairly rich assemblage of late Smithian (Early Triassic, Olenekian) ammonoids. The main species identified are Wasatchites tridentinus Spath, 1934, Wasatchites cf. distractus (Waagen, 1895), Anasibirites kingianus (Waagen, 1895), Arctoprionites nodosus (Frebold, 1930), Arctoprionites resseri (Mathews, 1929) and Xenoceltites subevolutus Spath, 1930. Two taxa are here discussed: Prionitid sp. and Arctoceras erebori sp. nov. The assemblage provides new information about the Early Triassic biostratigraphy and palaeogeography of the Boreal Realm. The composition of the Spitsbergen fauna is in good agreement with other assemblages within and outside the Boreal Realm and essentially comprises cosmopolitan taxa. Only Arctoceras erebori sp. nov. and Prionitid sp. are as yet restricted to Spitsbergen. The newly reported occurrence of low paleolatitude taxa from Spitsbergen strengthens the cosmopolitan distribution of ammonoids during late Smithian time, thus improving existing correlation.