The presence of the ichnospecies Arachnostega gastrochaenae Bertling, 1992 is documented from the Cambrian for the first time. it occurs in several stratigraphical levels of the “middle” Cambrian sediments in the Příbram-Jince and Skryje-Týřovice basins of the Teplá-Barrandian region in the Czech Republic. Simple tunnels as well as the complicated morphologies of Arachnostega were observed on internal moulds of trilobite exoskeletons and hyolith conchs and represent the oldest record of this ichnogenus. The Cambrian occurrences of rachnostega on skeletal body fossils evoke the connection between the Arachnostega-type feeding strategy and the sudden appearance of numerous skeletal animals. The development of the Arachnostega-type behaviour can be considered a feature of the “Cambrian substrate revolution.”
