New late Smithian (Early Triassic) ammonoids from the Lusitandiadalan Member, Vikinghøgda Formation, Svalbard.
Résumé
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.