Cambrian Trace Fossil Zoophycos from the Czech Republic

Abstract Lobate and helical ichnofossils attributable to Zoophycos found in Middle Cambrian shales of the Palác Hill in the Železné Hory Mountains (eastern Bohemia) represent the oldest occurrence of this ichnogenus. Such a complex Zoophycos became frequent during the Mesozoic but has been never recorded in strata older than the Ordovician. As such, they represent the oldest occurrence of helical Zoophycos. Besides Zoophycos isp. there is also a 15 cm thick sandy siltstone layer which is strongly bioturbated by Planolites isp., which seems unusual in a Lower Cambrian ichno-association.