Early Devonian actiniarian trace fossils (Conichnus conicus) from the Anti-Atlas of Morocco

摘要

Shaly and marly sedimentary rocks of late Lochkovian to Pragian and latest Emsian age yielded carbonatic conical structures several centimeters in size. These are filled with a coarse-grained bioclastic sediment with concentric conical fill-structures. We interpret these structures as the trace-fossil Conichnus, which usually is interpreted as a trace of soft-bottom dwelling sea-anemones (Actiniaria). These findings show that soft-bodied coelenterates were a common element of benthic ecosystems representing the softground marine Cruziana or Skolithos ichnofacies of the northern Gondwana shelf during the Early Devonian.