NEOICHNOLOGY AS ACTUALISM AND ITS USES IN PALEONTOLOGY

Actualism, the concept that modern physical processes give us the means for interpreting processes of the past, applies well to understanding both geological and biological processes. Moreover, biological and geological processes are often intertwined, particularly in surface environments. In this respect, neoichnology – the study of modern traces and their makers – is an effective tool for illuminating these interrelationships for application to paleontology. For one, modern traces give us search images for morphologically similar trace fossils, while also lending insights on past organismal behaviors we otherwise might not discern from body fossils alone. Neoichnology also encourages an appreciation of how modern organisms (from bacteria to whales) alter or otherwise affect surface environments via bioturbation, bioerosion, and biodeposition. The history of neoichnology as actualism in paleontology is surprisingly long, but became more apparent following 20^th century studies of organismal traces on the North Sea tidal flats and the Georgia coast. Georgia-coast neoichnology in particular bestowed generations of geologists with modern analogs for trace fossils in clastic sedimentary environments. Later, Georgia-coast neoichnology was augmented by neoichnological studies in shallow-marine carbonate environments of The Bahamas, which likewise directly connected to trace fossils from the relatively recent geological record there. In this study, we provide examples of modern traces from the Georgia coast and The Bahamas of plants, invertebrates, and vertebrates, ranging from terrestrial to marine settings, and compare these to analogous trace fossils. In such comparisons we acknowledge the limits of neoichnology within actualism, while also pointing towards its future utility for studies of invasion ecology, conservation biology, and climate change.