Ichnotaxonomic analysis of trace fossil assemblages of the Upper Triassic Nayband Formation, Tabas Block, Central Iran

Abstract

This study includes a thorough systematic analysis of the ichnological record in the Late Triassic siliciclastic Nayband Formation of the Tabas Block, Central Iran. A total of 48 ichnospecies representing 28 ichnogenera are identified and their preservation aspects, paleoecological aspects, producers and behavioral aspects are discussed. The ichnofauna includes Arenicolites, Asterosoma, Bergaueria, Chondrites, Cochlichnus, Cylindrichnus, Diplocraterion, Helminthopsis, Gordia, Gyrochorte, Lockeia, Macaronichnus, Monocraterion, Ophiomorpha, Palaeophycus, Paleodictyon, Phycodes, Phycosiphon, Planolites, Protovirgularia, Rhizocorallium, Rosselia, Scolicia, Skolithos, Taenidium, Teichichnus, and Thalassinoides. The high ichnodiversity and bioturbation intensity of the Nayband trace fossil suite seem to represent proliferation of epifaunal and infaunal habits, experiencing a high diversification of marine communities after the drastic reorganization of marine ecosystems during the Late Triassic. Further studies focused on the ichnologicalsignatures of these deposits will provide more detailed information to improve the current paleoecologic and paleoenvironmental interpretations of the Nayband Formation deposits.