TERRESTRIAL LANDSCAPE TAPHONOMY AND THE FUTURE FOSSIL RECORD

In comparison with patterns in the fossil record, the current biodiversity crisis has been called the “sixth extinction.” It has also become recognized that contemporary extinctions have a strong biogeographic signal, with island and endemic faunas being particularly hard hit. Meaningful comparisons of rates, ecological and taxonomic structure, and potential causal mechanisms of the modern extinction with those in the past depend on accounting for inherent biases present in the fossil record. Specifically, taphonomic biases should impact our understanding of preserved spatial patterns that are necessary to correctly interpret mechanisms of past extinctions. It is well recognized that the fossilization potential of terrestrial animals varies spatially, based on a range of climatic, topographic, and other environmental factors. For example, areas with caves and other karst features should preferentially preserve many mammals, since they act as traps for carcasses. Particular soil chemistries or local depositional settings may inhibit or promote fossilization over multiple time scales. Spatial variability of taphonomic processes should strongly but predictably overprint biological signals of animal abundance, diversity, and range. Placing taphonomic variables in an explicit spatial framework, where each map unit represents a specific combination of preservational controls, will produce a “landscape taphonomy” that will allow us to produce a “future fossil record” of living terrestrial vertebrates on the landscape scale, based on their spatial distribution and ecological properties and on the spatial variability of key taphonomic variables. This, in turn, will allow improved understanding of extinction patterns and mechanisms in the geological past.