Trace fossils in bathyal hardgrounds, Mediterranean Sea

Hardgrounds from the bathyal Mediterranean represent conditions of low net sedimentation and progressive cementation. Trace fossils preserved in the cemented crusts document the change in substrate consistency from softground through firmground to hardground. The studied material was dredged from stations at water depths of about ‐600 m to ‐4100 m. Trace fossils of the Glossifungites and Trypanites ichnofacies are well represented. The most important forms present are softground Chondrites isp., firmground Spongeliomorpha cf. S. iberica and Glossifungites saxicava, the agglutinated tube "Terebella” phosphatica encrusting hardgrounds, and the hardground borings Entobia isp., ?Maeandropolydora isp., ?Caulostrepsis isp., and three microborings attributed to fungi. The distribution of the ichnotaxa is markedly different in the eastern and western Mediterranean basins, respectively. This is consistent with the considerable oceanographic difference of the two basins. The eastern basin is particularly oligotrophic, and the hard‐grounds there generally show little or no bioerosion.