Bioerosion structures in high-salinity marine environments: Evidence from the Al–Khafji coastline, Saudi Arabia

摘要: Abstract Salinity is one the major stress factors that controls biotic activities in marine environments. In general, mixture with fresh-water has been mention as a great factor, but opposite, i.e. high-salinity conditions, less developed ichnological literature. Along Al-Khafji coastline, Saudi Arabia, hard substrates (constituted by gastropods, bivalves and coral skeletons) contain diverse abundant bioerosion traces associated encrusters. Field laboratory observations allowed recognition of eight ichnospecies belong to ichnogenera Gastrochaenolites, Entobia, Oichnus, Caulostrepsis Trypanites, which can be attributed various produced bivalves, sponges, gastropods annelids. The borings demonstrate two notable boring assemblages, namely, Entobia-dominated Gastrochaenolites-dominated assemblages. highly diversified encrustation studied organic substrate indicate long exposition period slow moderate rate deposition restricted (high-salinity) environment. This study shows high-salinity, at least for area, not an important controlling factor ichnology.