A glimpse into ancient food storage: Sequestrichnia and associated nucleocave Chondrites from Eocene deep-sea deposits

The old brickyard Velká nad Veličkou in the Czech Republic offers a unique insight into an Eocene deep-sea ichnoassemblage that is dominated by sequestrichnia. Secondary use of such food-stowing was made by the tracemaker of Chondrites intricatus as evidenced by its frequent penetration of the trace fossil Zoophycos brianteus and its occurrence preferentially on the surface of Zoophycos spreiten. Here, the Chondrites tracemaker presumably exploited the nutrient-enriched micro-environment (nucleocave). This close interrelations between Chondrites and Zoophycos support the hypothesis of a sequestrichnial behaviour of the Zoophycos producer. The studied locality also yields Helminthopsis tenuis, Tubulichnium mediterranensis, Scolicia strozzii, ?Dactyloidites isp., Megagrapton irregulare, and Planolites isp.