Marine Invertebrate Neoichnology

Trace fossils are an in-situ record of the infaunal ecosystem and can be used to constrain paleoenvironmental conditions at the time of animal colonization. However, in paleoichnological studies, the behavior of the perceived tracemaker is derived solely from trace-fossil morphology, which introduces significant uncertainty to interpretations. Neoichnology removes some of that uncertainty by linking modern infauna to the traces they produce, and by comparing infaunal and trace distributions to the physical and chemical conditions of the environment. Polychaetes, bivalves and crustaceans are the dominant infaunal groups in marginal-marine and marine settings. Echinoderms, holothurians and cnidarians are increasingly significant tracemakers in more fully marine (shelf) settings. The burrows made by select genera in these six groups, and variations in the diversity and density of burrowing as a function of physical and chemical stresses, are presented as analogs for paleoichnological studies.